Consider the following four algebraic expressions in the variable x:
(a) Part 1: (i) For each expression, state whether it is a polynomial in x or not. Give a clear reason for your answer in each case.
(b) Part 2: (ii) For every expression that is a polynomial, write its degree.
(c) Part 3: (iii) Among the given expressions, identify the one which has the highest degree and write that degree.