Aimee went to a stationary shop. She purchased 2 packs of red pens, 4 packs of black pens, and 3 packs of blue pens. The cost of each pack of pens was $2.50. Which expression shows the total amount Aimee spent on the pens?
A ($2.50 x 2 x 4x3)
B $2.50 x (2+4+3)
C($2.50 x 2) + 3+4
D (52.50 +2 +4+3)