The answer is B.
The pilgrims all meet at an inn in London before they go to make their way to Canterbury to worship at the shrine of Thomas a Becket. The owner of the inn is going to be going along also. He proposes a contest to help pass the time. He says that they will each tell tales. They will each tell two on the way down and then two more on the way back. Whoever tells the best one gets a free dinner at the inn when they return.
The pilgrims agreed to tell their tales, which will be judged by the Tabard Inn's innkeeper. The prize was a dinner, for which the rest of the pilgrims would pick up the tab.
The Canterbury Tales were written in 1386 by Geoffrey Chaucer.
In the original language, the portion about the prize for the best tale reads: