There are two boxes containing only blue and black pens. Box A has blue pens and black pens.
Box B has blue pens and black pens.

A pen is randomly chosen from each box.
List these events from least likely to most likely.
Event : choosing a blue pen from Box A.
Event : choosing a blue or black pen from Box A.
Event : choosing a blue pen from Box B.
Event : choosing a red pen from Box B.