Exercise 11.4.1: Building a generating function for selecting subsets from a heterogeneous set. About (a) Give a generating function denoting the number of ways to select a subset from a set of three identical apples. (b) Give a generating function denoting the number of ways to select a subset from a set of bananas. There are a total of four bananas, but they are bundled into two groups of two. (c) Now pool the apples and bananas. Give the generating function for the number of ways to select a subset from the pooled set.