Given the Fault Tree diagram and the probabilities P1=10-4, P2 = 10-7,P3 - 10- and P4 - 10-7 what is the probability P of the event to occur? Pa? Event AND PI Cause 1 OR P2 P3 P4 Cause 2 Cause 2 Cause 4 Select one: O a. 3 x 10-12 O 6.3 x 10-11 O C3 x 10-12 O d. 3 x 10-10