D. 2,400 sq. ft. is the closest
1) Convert mixed numbers to improper fractions...
6 1/12 = 73/121 and 11 5/6 = 71/6
2) To get area of one tile, multiply length x width...73/121 times 71/6 = 5,183/72 = 72 sq. in. or 6 sq. ft.
3) 6 sq. ft. times 408 tiles = 2,448 sq. ft.