Given the information in Example 8, answer the following questions:

(A) How many 4-officer committees with 1 senior officer and 3 junior officers can be formed?

(B) How many 4-officer committees with 4 junior officers can be formed?

(C) How many 4-officer committees with at least 2 junior officers can be formed?

Data from Example 8

A company has 7 senior and 5 junior officers. It wants to form an ad hoc legislative committee. In how many ways can a 4-officer committee be formed so that it is composed of

Any 4 officers?

4 senior officers?

3 senior officers and 1 junior officer?

2 senior and 2 junior officers?

At least 2 senior officers?