Beaufort Canal Has a Semi-Elliptical Cross Section with a Width

Multiple Choice

Beaufort Canal has a semi-elliptical cross section with a width W = 67 feet and a depth D = 13 feet (see figure) . The keel on Sasha's yacht rides 5 feet below the water line at the keel's deepest point. If the yacht travels parallel
To the canal, and assuming the canal is completely full of water, how close can Sasha bring the yacht's centerline
To the edge of the canal without running aground? (The keel is the very bottom of a boat hull and runs directly
Below the boat's centerline from front to back.)

A) 4 ft
B) 5 ft
C) 12 ft
D) 21 ft