The answer is A because -4 squared does not equal -16 as the equation expresses. B is squaring positive 4, when we are trying to find the result of squaring -4 C and D We are not squaring 16 or -16 because. If we did so that would give you 4 nor the answer you are looking for.
(A) because if you have an even number despite dealing with a negative when using exponents you get positive, because a negative times a negative gives you a positive. Odd number however don't give you bunches of 2 so when dealing with negative numbers there's and extra negative that is factored in and will always make your answer negative.