Which of the following algebraic expression is not a polynomial? * A. 8^2 B. 〖3x〗^(-2) C. 2+x D. 7/3^2

Which of the following algebraic expression is a polynomial? *
A. 5^(2-x)
B. 〖4x〗^(-2)+1
C. 2+x
D. 7/x^2​