Which option directly compares unequal units in studying India's size?

Correct answer: (3.28) million sq km and (3214) km

Different measurements cannot be compared directly unless their units and meanings are understood. Square kilometres measure area, which covers a surface, while kilometres measure length or distance along a line. They are not the same kind of quantity. A value in million square kilometres therefore describes the size of an area, whereas a value in kilometres describes a distance such as length, width, or coastline.

Option C directly places 3.28 million square kilometres beside 3214 kilometres, so it compares unequal types of units. Options A, B, and D compare values that are all written in kilometres, even though their geographical meanings may differ. The educational point is not which number is larger, but whether the units represent comparable quantities. Hence C is correct.