6) Given only the number of users in 2005 and the assumption that the number of users triples each year, how did you determine the number of users for years 0,-1, -2, and -3?
a. Divide the next year's number of users by 2.
b. Halve the next year's number of users.
C. Divide the next year's number of users by 3.
d. Subtract 3 from the next year's number of users.