The polynomials can´t contain:
-Variables in the exponents of the terms.
-Variables in the denominator.
- Negative exponents.
-Fractionals exponents.
-The variables cant be as radicals.
Therefore:
a) It is a polynomial (The variable is under a radical)
b) It is not a polynomial.
c) It is a polynomial.
d) It is not a polynomial. (It has a variable in the denominator).
e) It is a polynomial.
f) It is not a polynomial. (It has a variable in the denominator).