I am going to execute this code of stack methods:

Stack s$=$ new Stack$)$;

s$.$push$(2)$; s$.$push$(1)$;

System.out.printin$($s$.$pop$())$:

System.out.printIn$($s$.$top$())$;

s$.$push$(3)$;

Suppose that s is represented by an array list. The state of the private instance variable

top of s after the above code:

$20$

None of the above O

$о$ O

$1$