Maybe c or A not completely sure try looking for the one you think it is and try reading it again
1 hour is 15m
2 hour is 30m
3 hour is 65m
4 hour is 80m
1/5 is equal to the 20% of the trip and that took 45 minutes.
45minutes/20% of traveled distance = X minutes/ 100% travel distance
2.25 * 100= X
225= X
So if for the 1/5 or 20% of the trip lasted 3/4hour or 45 minutes. To complete the trop you need 225 minutes or 3 hours and 45 minutes or 3 3/4 hours.
Circumference of circular path=pi*d^2/4
=44.156
length of light=1.45
light needed=44.156/1.45
=31 approx