Final answer:
An ointment is a semisolid dosage form with an oily base used for topical application on the skin, providing a protective barrier and medication delivery.
Correct option is C
Step-by-step explanation:
A semisolid dosage form with an oily base is referred to as an ointment. Unlike creams, which are semi-solid emulsions that can either be oil-in-water or water-in-oil, ointments are of heavier consistency and typically do not contain water. They are used for topical application on the skin and provide a barrier to protect the area and assist in medication delivery.
Creams, on the other hand, are more easily washed off and are not as greasy as ointments. Lotions are low-viscosity preparations intended for the skin with typically a higher water content than creams and can be spread easily over a large area of the skin.