There are only two possible perfect squares 4 and 9. The cases corresponding to sum being equal to 4 are (1, 3), (2, 2), and (3, 1), where the first entry represents the number on the first die and second number on the second die, totaling 3, And that for the sum being equal to 9 we have (3, 6), (4, 5), (5, 4), and (6, 3), totaling 4.
The required case are (1, 3), (3, 1), (3, 6), and (6, 3), hence total of 4 cases.
Required probability is therefore 4/36. Option A.