Answer:
None of them
Explanation:
A polynomial must have a pronumeral that is to the power of an integer, and you can't divide by a variable such as 2/x so for
a) there is a
which means it's not a polynomial as
is the same as

b) The second term is being divided with a variable so that can't be a polynomial
c) There is a
so it can't be a polynomial
d) There is a
so it can't be a polynomial