For which data set is the mode most useful?

A.{ 8, 12, 8, 14, 14, 20 }
B. { 1, 2, 3, 4, 5 }
C. { 32, 36, 41, 36, 40}
D. { 4, 4, 6, 6, 8, 8 }

One cell phone plan charges $20 per month plus $0.15 per minute used. a second cell phone plan charges $35 per month plus $0.10 per minute used. write and solve an equation to find the number of minutes you must talk to have the same cost for both calling plans.