Cindy has 26 nickels. She is getting rolls of nickels from the bank. She has enough money to get up to 10 rolls of nickels, and each roll contains 40 nickels. The bank will not give partial rolls. The function that models the number of nickels Cindy will have after leaving the bank is f(r)=40r+26, where r is the number of rolls of nickels she gets.

What is the practical domain of the function?

A. {66, 106, 146, 186, 226, 266, 306, 346, 386, 426}
B. all real numbers
C. r>1
D. all integers from 1 to 10, inclusive