A grocery store sells whole milk and low-fat milk in half-gallon containers. A half-gallon of whole milk costs $3.75 and a half-gallon of low-fat milk costs $4.25. During a typical week, 128 half-gallon cartons of milk were sold bringing in total revenue of $516 to the grocery store. Which of the following systems of equations could be used to find the number of half-gallon cartons of whole milk, W, and the number of half-gallon cartons of low-fat milk, L, that were sold at the grocery store?