The team may have lost the game / they gained an invaluable lesson in the importance of character.

a), yet
b), and
c), for
d), so

Which word do you think fits best between the clauses?

The two independent clauses are setting up a contradiction or opposites. Which conjunction will you use?

http://grammar.ccc.commnet.edu/grammar/conjunctions.htm

The correct answer is b), "and".

To determine the correct answer, you need to consider the meaning of the sentence and the relationship between the two clauses "The team may have lost the game" and "they gained an invaluable lesson in the importance of character."

In this context, the use of "and" indicates a continuation or addition of information. It shows that both clauses are independent and contribute equally to the overall meaning.

To answer this question correctly, you should understand that the sentence is presenting two contrasting ideas: the team losing the game and gaining a valuable lesson. The word "and" is the most appropriate conjunction to connect these two ideas, as it implies that both events happened simultaneously.