Final answer:
MLK's group, the SCLC, probably anticipated unease from the SNCC during their activities in Selma due to differing approaches to activism and strategy.
Step-by-step explanation:
MLK's group, the Southern Christian Leadership Conference (SCLC), believed that the fellow protest group which would be unhappy to see MLK the next day in Selma would most likely be the Student Nonviolent Coordinating Committee (SNCC). The SNCC may have felt some unease given that their activist strategies had begun shifting towards a more radical and confrontational approach compared to the SCLC's persistence on nonviolent tactics. Additionally, divisions had been growing among civil rights organizations, with groups like the SNCC and CORE moving towards more youthful and aggressive methods, in contrast to the NAACP and SCLC's more conservative and legal-focused strategies.