Verify each function
option a -----> is not a polynomial (variable doesn't have a positive integer exponent)
option b ---> is not a polynomial (variable has negative integer power)
option c ---> is a polynomial (is a function that involves only non-negative integer powers or only positive integer exponents of a variable in an equation)
option d ---> is a polynomial function ( is a constant)
therefore
The answer is
options c and d