What will be printed?

Hashset $$ Integer $>$ numbers $=$ new Hashset $$ Integer $>()$;

numbers.add$(1)$;

numbers.add$(2)$;

numbers.add$(3)$;

numbers.add$(2)$;

numbers.add$(1)$;

System.out.println$($numbers$.$size$())$;

What is true about the code below?

ArrayList $$ Integer $>$ numbers $=$ new ArrayList $$ Integer :;

numbers.add$(1)$;

numbers.add$(2)$;

numbers.add$(3)$;

Iterator $$ Integer $>$ iterator $=$ numbers.iterator $()$ ;

while $($iterator$.$hasNext$())\{$

int number $=$ iterator.next $()$ ;

iterator. remove$()$;

$3$

System.out.println$($numbers$.$size$())$;

none of these is correct

the code will print $3$

the code will not compile

the code will crash

the code will print $0$