The rainfall for the month of July was above average. The water level in a small lake measured 834 feet at the beginning of the month. Due to all the rainfall, the water level rose 35 of a foot per week for the first three weeks, then the lake dropped 12 foot in the last week of the month. What was the water level of the lake at the end of July?
A
979ft.

B
101120ft.

C
10120ft.

D
71120ft.