Though this question is subjective a decent amount, I would choose Choice B for this one.
Reasoning:
A - It wouldn't further the advance of a group collaboration, as it may hold back the group instead.
B - It continues the dicussion by building upon the previous person's point, therefore this is likely the correct answer.
C - It would insult the other person within the group rather than convicing them your building on their point.
A - It wouldn't further the advance of a group collaboration, as it may hold back the group instead.
