Chris mixed 4 pounds of raisins with 4 pounds of nuts. If a pound of nuts costs 3 times as much as a pound of raisins, then the total cost of the raisins was what fraction of the total cost of the mixture?
Choose the correct choice from the following options:
A) 1 / 7
B) 1 / 5
C) 1 / 4
D) 1 / 3
E) 3 / 7

Rationale: "1 lbs of raisin = $ 1 4 lbs of raisin = $ 4 1 lbs of nuts = $ 3 4 lbs of nuts = $ 12 total value of mixture = 12 + 4 = 16 fraction of the value of raisin = 4 / 16 = 1 / 4 ans : c"
Answer: C