Given an empty Stack S$,$ what is the top element once the following operations are executed?

push$(18),$ push$(13),$ push$(5),$ pop$(),$ pop$(),$ peek$(),$ push$(19),$ pop$(),$ push$(12),$ push$(25),$ pop$(),$ peek$(),$ push$(16),$ pop$(),$ push$(9),$ push$(4),$ pop$()$

Question $6$ options:

A$)$

$4$

B$)$

$16$

C$)$

$9$

D$)$

$25$