Answer: B) established a rhythm and required cooperation.
Enslaved laborers did not have much leisure time in order to have hobbies, or meet various different people. Their social circle was reduced to the people they worked with, and their hobbies were those that did not take them away from their work. Call-and-response songs were the perfect distraction and enjoyment for their difficult lives. The fact that the songs are rhythmic and repetitive meant that they could serve as motivation for a repetitive job, such as picking cotton. Moreover, the fact that they required cooperation contributed to their sense of community.
B) established a rhythm and required cooperation. All of the other answer choices don't really fit like this because why else would those songs help them?