The correct answer is option 3, Paracetamol. Paracetamol is a common drug used to control fever. It works by blocking the production of certain chemicals in the brain that cause fever and pain. It is also known as acetaminophen. Paracetamol is often used to reduce fever in adults and children and is considered safe when taken at the recommended doses.

Option 1, Ibuprofen, is a nonsteroidal anti-inflammatory drug (NSAID) that can reduce pain and inflammation but it may not be as effective as Paracetamol in controlling fever.

Option 2, Penicillin, is an antibiotic used to treat bacterial infections and is not typically used to control fever.

Option 4, Corticosteroid, is a type of medication that can help reduce inflammation but is not commonly used to control fever unless there is an underlying inflammatory condition causing the fever.

In summary, Paracetamol is the drug commonly used to control fever.