To satisfy the requirement that the planning committee must consist of 12 students, with at least 2 students from each class, we can evaluate each option:
A. 1 freshman and 11 sophomores
- This does not meet the requirement of having at least 2 students from the freshman class. Not viable.
B. 5 freshmen and 7 sophomores
- This meets the requirement of having at least 2 freshmen and 2 sophomores. Viable.
C. 6 freshmen and 4 sophomores
- This also meets the requirement of having at least 2 freshmen and 2 sophomores. Viable.
D. 0 freshmen and 12 sophomores
- This does not meet the requirement of having at least 2 freshmen. Not viable.
From the options given, the viable solutions are B (5 freshmen and 7 sophomores) and C (6 freshmen and 4 sophomores).