How many significant figures are in the measurement 20,500 liters?

a. 4
b. 3
c. 2
d. 0

This is the concept of arithmetic. Significant figure is each of the digits of a number that are used to express it to the required degree of accuracy, starting from the first nonzero digit. Thus the value of 20,500 liters, has 3 significant figures counting from 5.
The answer is B] 3

Why are u not just putting the numbers this is to much