An 8-foot by 10 -foot floor is tiled with square tiles of size 1 foot by 1 foot. Each tile has a pattern consisting of four white quarter circles of radius 1 / 2 foot centered at each corner of the tile. The remaining portion of the tile is shaded. How many square feet of the floor are shaded?
Answer Choices
A. 80-20 \pi
B. 60-10 \pi
C. 80-10 \pi
D. 60+10 \pi
E. 80+10 \pi