The rainfall for the month of July was above average. The water level in a small lake measured 8 3/4 feet at the beginning of the month. Due to all the rainfall, the water level rose 3/5 of a foot per week for the first three weeks, then the lake dropped 1/2 foot in the last week of the month. What was the water level of the lake at the end of July?
A. 7 11/20 ft
B. 9 7/9 ft
C. 10 1/20 ft
D. 10 11/20 ft