Answer:
C. a number whose square root is a whole number
Step-by-step explanation:
A number whose square root is a terminating decimal is not a perfect square.
A negative whole number cannot be a perfect square.
A number times itself is squared, the number itself is not a perfect square.
The correct answer is option C, a number whose square root is a whole number. For example: 4 is a perfect square.

The square root of a perfect square is always a whole number.