What are the set of functions that are to be executed to get the following output?
cat

A. push(c, s); push(a, s); push(t, s);
pop(s); pop(s); pop(s);

B. push(c,s); pop(s); push(a,s); pop(s);push(t,s);pop(s);

C. pop(c ); pop(a); pop(t);

D. push(c,s); push(a,s); pop(t);

Answer: Option B