If waste materials contaminate the source of drinking water, the most likely disease to spread is Typhoid. Typhoid is caused by the bacteria Salmonella typhi and is transmitted through contaminated food and water. When waste materials, such as sewage or industrial waste, contaminate the source of drinking water, the bacteria can enter the water supply and infect humans who consume the contaminated water. Scurvy, on the other hand, is caused by a deficiency of vitamin C and is not related to water contamination. Malaria is transmitted through mosquito bites and is not directly tied to contaminated water. Similarly, anaemia is a condition caused by a lack of healthy red blood cells and is unrelated to water contamination. Therefore, the correct answer is option 2: Typhoid.