Crafty Bill's Cool Car Sales Opened as a Used Car

Multiple Choice

Crafty Bill's Cool Car Sales opened as a used car sales lot in 2006. The graph shows the number of cars sold as a function of time. What is the domain of this function if we consider only the indicated points?

A) {2005, 2011}
B) {2005, 2006, 2007, 2008, 2009, 2010, 2011}
C) {2006, 2007, 2008, 2009, 2010}
D) {2006, 2010}