To express the population of 15,386 in two significant figures:

1. Identify the first two significant digits: The first two significant digits in 15,386 are 1 and 5, which makes the number 15.

2. Round the remaining digits: The digit following 15 is 3 (which is less than 5), so we round down.

3. Convert to the nearest value: 15 rounded to the nearest thousand is 15,000.

Thus, the population of 15,386 expressed in two significant figures is:

D. 15,000