Question 9 Not yet answered Suppose that Sl and S2 are empty stacks and al, a2 and a3 are objects. What do the stacks contain after executing the following sequence of operations? Sl.push(a2); Marked out of 2.00 Flag question Si push(al); S2.push(a3); S2.push(Sl.pop(); S2.push(Sl.peek): Select one: a. Si=1) and S2=0) O b. Si=[a2] and S2=[a3 al a2] O c. Sl= [a2, al ] and S2= [a,3,a3, al ] O d. NONE