Answer:
D
Explanation:
First we need to figure out how many people are going on the field trip
if each class has 27 people going and there are 6 classes, 6*27=162
162 ppl are going. If 3 buses can hold 48 ppl then 3*48=144
3 buses are not enough, if we were to bring in one more bus 4*48=192
there would be enough place for everyone