Which of the following is the topic sentence of paragraph 3?

4. Which of the following is the topic sentence of paragraph 3?
A. The canoe took more kinds... pack animals.
B. The use of canoes in large numbers... Lake Chad.
C. Passengers could also sleep and prepare their meals on board.
D. The best method of river transportation was by canoes.
5. An alternative title for this passage is...
A. Water travel.
B. River travel.
C. Water transportation.
D. Advantages of canoe transportation.