4. (a) (12%) You are given the following C-like code. int foo (int *p) { } *p = 1; return 2; int bar (int *p) { } *p = 3; return 4; int main() { } int x = 10, y; y=x+foo (&x) + bar (&x); // Statement A There are at least three ways to evaluate the expression in statement A that results in variable y taking three different values. Briefly elaborate the three ways and state the value of y after each way of evaluation. (b) (5%) Write a function in C that has no functional side effect but is not referential transparent. Your function cannot have any print statements. State the semantics of your function. (c) (4%) In C or C++, evaluating the expression a=a++ produces undefined behavior. Give a reason to justify this design.