Correct answer is A.
A die is tossed twice,
The probability of getting a 4, 5 or 6 in the first trial is 3/6 = P(A)
The probability of getting a 1, 2, 3 or 4 in the second trial is 4/6 =P(B)
As the events are independent, the probability of these two events together will be, P(A).P(B) = 1/3.