Answer:
i think that B..is a right answer
The conversion factors are 42 gallons in a barrel
4 quarts = 1 gallon. I use unit analysis to get answers for questions like these.

All the units are in the numerator. There are 120 * 42* 4 = 20160 quarts in 120 barrels.
3
The period is the amount it time it takes to make one complete cycle. If we start at 0 for simplicity sake, the graph is at its maximum point. It reaches its maximum point again at 3, this is one complete cycle and thus the period is 3.
Round 396.6 to 396, because 396/9=44, making a whole number. Hope this helps!!