Answer:
b. agreeing to a no-strike pledge.
Explanation:
One of the effects of World War II in the United States is that it led to the unification of many sectors of the population. There was a sense of unity that arose due to the fight against a common enemy. This feeling arose within the labor movement as well. During the war, leaders from the AFL and the CIO (two very influential unions) joined together and decided to sign a "no-strike pledge" for the duration of the war, in order to ensure that the war effort was not interrupted.