An office supply store has 5 different packages of black ink pens. Which is the best deal available on black ink pens at this office supply? BLACK INK PEN PRICES

4 pack for $7.00
6 pack for $10.25
10 pack for $ 13.00
12 pack for $ 15.00
25 pack for $32.50

answer choices:

a) 4 pack for $7.00
b) 6 pack for 10.25
c) 10 pack for $13.00
d) 12 pack for $15.00