When a die is thrown, what is the probability of getting a perfect square?

The possible outcomes when a die is rolled are {1, 2, 3, 4, 5, 6}

Thus, total number of outcomes = 6

Now, favouravble outcomes, i.e. perfect squares are {1, 4}

Thus, number of favourable outcomes = 2

$\therefore$P(getting a perfect square) $=\frac{\mathrm{number} \mathrm{of} \mathrm{favourable} \mathrm{outcomes}}{\mathrm{total} \mathrm{number} \mathrm{of} \mathrm{outcomes}}=\frac{2}{6}=\frac{1}{3}$

Hence, the correct answer is $\frac{1}{3}$.