A)4/x+x/7
B)x^-4
C)-4/7
D)x^2-4+7x
A)4/x+x/7
B)x^-4
C)-4/7
D)x^2-4+7x
A and B are not polynomials because they each include one term that has a negative exponent
(Note: 4/x = 4x^{-1}).
C and D are polynomials (C is constant, D is quadratic).
Answer: B), since the exponent cannot be negative for a polynomial.