Assume you have a stack called S with the following contents, and trace the following operations:

2 (top)

4

3

7

9

System.out.println(S.peek()); //a) What is printed?

S.pop();

System.out.println(S.peek()); //b) What is printed?

System.out.println(S.pop()); //c) What is printed?

System.out.println(S.peek()); //d) What is printed?

//e) What are final the contents of the stack?