To solve this problem, we need to determine the number of favorable outcomes and the total number of possible outcomes when selecting one number from each set.

Given:

Set A = {2, 3, 4, 5}

Set B = {11, 12, 13, 14, 15}

We are asked to find the probability that the sum of the two numbers selected from each set equals 16.

First, let's identify how many pairs from Set A and Set B yield a sum of 16:

2 (from A) + 14 (from B) = 16
3 (from A) + 13 (from B) = 16
4 (from A) + 12 (from B) = 16
5 (from A) + 11 (from B) = 16

Thus, there are 4 favorable pairs.

The total number of possible outcomes is the product of the number of elements in Set A and Set B:

$$ |A| \times |B| = 4 \times 5 = 20 $$

The probability (P) that the sum of the two numbers equals 16 is given by the ratio of the number of favorable outcomes to the total number of possible outcomes:

$$ P = \frac{\text{Number of favorable outcomes}}{\text{Total number of possible outcomes}} = \frac{4}{20} = \frac{1}{5} = 0.20 $$

Therefore, the correct answer is Option A: 0.20.