Option A,C and D are not polynomials.
Explanation:
Polynomial functions are given by
p(x) = a₀ + a₁x¹+ a₂x²+ ...........+aₙxⁿ
Where a₀, a₁, a₂, ..., an are constant coefficients and n is non negative integer.
Option A

Here one exponent of x is -2, so this is not a polynomial function.
Option B

Here all the exponents are non negative integer, so this is a polynomial.
Option C

Here one exponent of x is 0.5, so this is not a polynomial function.
Option D
p(x)= x⁻²+x+1
Here one exponent of x is -2, so this is not a polynomial function.
Option E

Here all the exponents are non negative integer, so this is a polynomial.
Option A,C and D are not polynomials.