Waiting for answer This question has not been answered yet. You can hire a professional tutor to get the answer.
Which are those two vectors whose resultant vector is zero?
Two opposite vectors (opposite directions) of same magnitude give you a zero resultant.
In Physics, consider a force (a person pulling) on a crate and another force acting upon the same crate in the opposite direction give a zero resultant (basically if the crate was at rest remains at rest):