'RNA interference (RNAi)' technology has gained popularity in the last few years. Why? 1. It is used in developing gene silencing therapies. 2. It can be used in developing therapies for the treatment of cancer. 3. It can be used to develop hormone replacement therapies. 4. It can be used to produce crop plants that are resistant to viral pathogens. Select the correct answer using the code given below.

Describes biomedical research linking hormones and viruses to cancer, showing cancer can have specific molecular causes.

A student could combine this with the basic fact that RNAi silences specific genes to reason that if cancer depends on particular genes/pathways, RNAi might be used to target them.

Lists multiple anticancer agents derived from biological sources, illustrating that molecularly targeted compounds can treat cancer.

A student could extend this by noting that therapies can act on molecular targets and therefore explore whether RNAi (a molecular tool) could be used similarly to inhibit cancer-promoting genes.

Notes that new drug therapies dramatically lowered disease death rates, demonstrating that novel therapeutic approaches can change cancer/outcome landscapes.

A student could infer that development of new modalities (like RNAi-based drugs) is a plausible route to improved cancer therapy and then check feasibility/clinical progress.

Explains that therapies for non-communicable diseases focus on managing symptoms, early diagnosis and continuous care, implying varied therapeutic strategies are used depending on disease mechanisms.

A student could use this to motivate investigating whether RNAi would be suited as a mechanism-based therapy (versus symptomatic) for cancers with identifiable gene drivers.

Shows that environmental factors (UV-B) can alter immune responses and contribute to cancer, indicating cancer involves biological pathways amenable to intervention.

A student could combine this with the concept of gene/pathway modulation (via RNAi) to consider targeting pathways altered by environmental carcinogens.

Defines GM crops as plants whose DNA has been modified and lists 'Resistance to bacteria, virus and other components' as a benefit of genetic engineering.

A student could extend this by noting RNAi is one form of genetic modification that can be designed to target viral genes, then seek experimental reports or trials that introduce RNAi constructs into crops and test virus resistance.

Describes artificial selection and creation of new seeds via human techniques (hybridisation) that produce disease- and pest-resistant varieties.

A student can generalise that human-directed genetic changes (including engineered approaches like RNAi) are an accepted route to create disease-resistant plants and then compare methods and efficacy.

Emphasises that genetic modification (useful selection of genes and screening wild relatives) yields improved, disease-resistant plant varieties.

One could treat RNAi as another tool for altering gene function and then evaluate whether targeting viral sequences via RNAi could produce similar 'improved' resistant varieties in trials.

Explains vegetative propagation produces genetically similar plants, implying that any engineered trait introduced into a parent (e.g., via genetic modification) can be uniformly propagated.

A student might infer that once an RNAi-based resistance trait is introduced into a plant line, vegetative propagation would produce many uniform resistant plants to test field performance.

Lists 'Production of disease-free and genetically better transplants' as an objective of protected cultivation, linking disease control with use of improved/genetic approaches.

This supports extending the idea that engineered disease-resistance methods (e.g., RNAi constructs) could be deployed in nursery/seedling production and evaluated for reduction of viral incidence.