Kitty Foods sells their cat food in 3 3/4 lb bags, while Cat Caterers sells 2 1/8 lb bags. How much bigger are the bags Kitty Food sells than those sold by Cat Caterers? Reduce your answer to lowest terms.
A. 1/2 lb
B. 5/8 lb
C. 1 5/8 lbs
D. 1 1/2 lbs