Directions for questions 1 to 4: The instructions given below is followed by a set of four questions. Choose the most appropriate answer to each question.

Caselet: A company has four projects (P1, P2, P3, P4) and six employees (A, B, C, D, E, F). Each project must have exactly 2 employees assigned to it. The following constraints apply:

1. Each employee is assigned to exactly two different projects.
2. A and B are never on the same project.
3. C must be on both P1 and P3.
4. E is assigned only to P2 and P4.
5. F is not assigned to P3.