**Concept:** The question tests on the basics of Probablity

**Solution:**

If A is not in the committee, then the number of ways of choosing 3 people out of 4 = 4C3 = 4 ways

Total number of ways = 5C3 = 5C2 = 5 * 4 / 2 = 10 ways

probability = Favorable outcomes / Total Outcomes = 4 / 10 = 2/5**Option C**