A virus is spreading by a factor of 2 every hour from 1:00 p. m. to 11:00 p. m. The function below shows the number of viral infections, f(x), after x hours from 1:00 p. m.: f(x) = 20(2)x

Which of the following is a reasonable domain for the function?

All positive integers
1 ≤ x ≤ 11
0 ≤ x ≤ 20
0 ≤ x ≤ 10