9. Bob's preferences for water (w) and coke (c) can be described by utility function U(w, c) = In(w) +c, MU. = 1, MU. =1. But now the price of Coke suddenly increased to $8 per can. If the price of a water is $1 and the price of a coke is $8, and Bob has $4, find Bob's optimal consumption bundle. (a) w = 8, c= - (b) w =4, c=0 (c) w =0, c= 2 (d) w =4, c= 2 (e) None of the above