A bus averages 60 mi/h traveling to its destination in the first half of its trip through an expressway and 72 mi/h in the second half traveling through a motorway. What is the bus's average speed for the entire trip rounded to the nearest tenth?
A) 64.2 mi/h
B) 63.0 mi/h
C) 65.5 mi/h
D) 66.0 mi/h