In which of the following will you be able to buy the lowest cost per pencil?

store a
$110 for 88 pencils.

store b
c = 1.10p, where c is the total cost of the pencil and p is number of pencils

store c
no. of pencils.
25 = $50.00
32 = $64.00
56 = $112.00

store d
(look at the graph)