Daniel is printing out coples of a presentation. It takes 3 minutes to print a color copy and 1 minute to print a black-and-white copy. He needs to print at least 6 copies and must have the copies completed in no more than 12 minutes. If the solution region represents the number of color copies and black-and-white copies that Daniel can print, determine which graph represents the solution set to the system of inequalities representing this situation.