The correct answer is option 4 - taking. In the given sentence, the blank needs to be filled with a word that means consuming or ingesting medicine.

Option 1 - eating: While eating can refer to consuming food, it is not the appropriate word to use when referring to taking medicine.

Option 2 - gulping: Gulping means swallowing quickly or in large amounts, but it doesn`t specifically refer to taking medicine.

Option 3 - swallowing: Swallowing is the action of moving something from the mouth down into the stomach through the esophagus. While taking medicine often involves swallowing, it is not the best word choice for this context.

Option 4 - taking: This is the correct answer. Taking medicine means consuming or ingesting medication, which accurately represents the action of patients consuming medicine. Many patients tend to stop taking medicine as soon as they start feeling better, which can be detrimental to their health.