The caterer at a brunch bought several pounds of chicken salad and several pounds of tuna salad. The chicken salad cost $9 per pound, and the tuna salad cost $6 per pound. He bought a total of 14 pounds of salad and paid a total of $111. How much chicken salad did he
a) 6 pounds
b) 7 pounds
c) 8 pounds
d) 9 pounds