Alumber yard has five different lengths of 2 by 4 boards. based on cost per linear foot, which is the best deal available on 2 by 4 boards at this lumber yard?

2 × 4 board prices
8 foot board for $2.95
10 foot board for $3.15
12 foot board for $4.10
16 foot board for $5.80
20 foot board for $6.95

a) 8 foot board for $2.97
b) 10 foot board for $3.25
c) 12 foot board for $4.10
d) 16 foot board for $5.80