Actually A and B are not independent because knowing information about B (that the number <3) means that there is a 1/2 chance of getting a prime number
P(A|B) = 1/2
P(A|C) would be given that an odd number appears, whats the chance that the number is prime
P(A|B^C) would be, given that the number is less than 3 and its odd, what are the chance that its prime