Option A is correct
Here, we want to select which of the expressions is a polynomial
Generally, we need to understand that a polynomial does not have negative powers
This eliminates the last option as we can see negative power of x in the expression
Furthermore, the second option cannot be considered a polynomial. This is because we have more than one variable present (y in this case is not a constant but a variable)
Also, looking at the third option, we can rewrite what we have here as;
[tex]6(x-2)^{-1}[/tex]This leads to a case of negative power too
So the correct answer is the first option which follows the general form of polynomials;
[tex]a_0+a_1x\text{ + }\ldots+a_nx^n[/tex]