Answer:
C
Step-by-step explanation:
Polynomials should consist of only non-negative integer powers of x. Thus B and D are definitely not. It might be possible to simplify A into something that looks like a polynomial, but it’s a bit difficult. If you just need to choose one, then C is definitely a good choice.
My incomplete attempt of factorizing A:
[tex]\frac{x^5(x^6-4)}{x^5(x^{-5}+1)} = \frac{x^5}{1+x^5}(x^3+2)(x^3-2)[/tex]
