Kevin purchased the following shares of Alpine stock: 54 shares for $1,546.49 in 2011, 67 shares for $1,789.59 in 2012, and 98 shares for $2,435.37 in 2013. He sold 133 shares of Alpine in 2015 and did not identify which shares he sold. What basis should he use for computing gain or loss.

a) $3,355

b) $3,497

c) $3,511

d) $3,643