Answer:
Step-by-step explanation:
First, what's a polynomial? It's an algebraic expression whose only independent variable is x, and in which all the x powers are either zero or positive and are integers: x^3, x^2, x^1, x^0 (for example).
Looking at possible answer choice A, we immediately reject this because that power of x is in the denominator, representing 2x^(-3). This negative power of x is not allowed. Reject A.
In B, we have the powers x^2, x^1 and x^0. Great. This is a polynomial.
In C, we have x^2 + 1 in the denominator of the final fraction. Reject this because of the final term.
In D, we have x^2 + 2x + √
