Computer Science. Suppose elements "yellow", "pink", "blue", and "red" are pushed onto the stack in that order. Which orders of events could occur?:

$-$"blue" is popped after "pink"

$-$"pink" is popped before "red"

$-$"pink" is popped after "red"

$-$"yellow" is popped first

$-$"blue" is popped before "yellow"