A, B, C, and E are not polynomials.
A polynomial is an expression involving exponents, constants, and variables, so long as:
You are not dividing by a variable.
You are not raising a variable to a power of a negative number.
You are not raising a variable to a power of a fraction.
You are not taking the root of a variable.
Only one of these satisfies the criteria for a polynomial, and that is D. However, the 2nd term, 0x^2 is an unnecessary term, and would only be included if dividing this polynomial by another polynomial.
