Why did the watchmen retreat? a. they were cowards b. they remembered the last murder c. they bribed before hand by the pirates d. they were informed earlier about mr. taft’s plan

D). They were informed earlier about Mr. Taft’s plan.

Explanation:

The watchman retreated as they had been informed previously about Mr. Taft's plan. The evidence to this claim is provided within the sentence as it says "wisely retreated" and "it was in the plan for them to retreat" that clearly portrays the purpose of watchman and Mr. Taft to withdraw their boat "before so overwhelming a force". Thus, option D is the correct answer.

why does the crew join ahab's quest without hesitation?

i think it could possibly be b