The correct answer is b. The James Madison Memorial Building, built in 1981, houses the Folger Shakespeare Library
In this case, it is correctly used because the "built in 1981" is an apposition separated with commas.
I would most likely choose a bar graph, because each bar would belong to it's own career, and it would give a good overall visual of how the career interests compare.
Knots usually take 1 minute or so to do. If you keep on tying the knots and get used to the pattern, you will get faster and faster and eventually will be able to do it in 4 seconds. It is kind of like picking strawberries. If you keep on picking strawberries and timing yourself, you will get faster like when you typed the knot