Answer:
B. The group determined to publicize their objections to the hostilities in Vietnam and their support for a truce by wearing black armbands during the holiday season.
Step-by-step explanation:
The excerpt that supports this answers says:
"In December 1965, a group of students in Des Moines held a meeting in the home of 16-year-old Christopher Eckhardt to plan a public showing of their support for a truce in the Vietnam war. They decided to wear black armbands throughout the holiday season and to fast on December 16 and New Year's Eve. "