If x and y are perfect squares, then which two of the following is not necessarily a perfect square?  Choose the correct choice from the following choices:	A) x^2	B) xy	C) 4x	D) x+y	E) x^5
If x=y=1^2=1, then each option but C is a perfect square, therefore C is NOT necessarily a perfect square.   Answer: 4x.
<result>C</result>
If x and y are perfect squares, then which two of the following is not necessarily a perfect square?