Among the N = 18 doctors in a healthcare group, A=7 of them are board certified. A team of n= 4 doctors is going to be selected at random to staff a new clinic. Use X to represent the number of doctors selected into the team who are board certified. Keep at least 4 decimal digits.

A. The probability that exactly x=2 doctors selected into the team are board certified is

B. the probability that exactly x=3 doctors selected into the team are board certified is

C. The probability that exactly x=1 doctor selected into the team is board certified is

D. The probability that at most 2 doctors selected into the team are board certified.