For three events A, B and C, P(Exactly one of A or B occurs) = P(Exactly one of B or C occurs) = P(Exactly one of C or A occurs) = 1/4 and P (All the three events occur simultaneously) = 1/6. Then the probability that at least one of the events occurs, is :
(1) 7/32
(2) 7/16
(3) 7/64
(4) 3/16