A surveyor standing 68 meters from the base of a building measures the angle to the top of the building and finds it to be 40°. The surveyor then measures the angle to the top of the radio tower on the building and finds that it is 49°. How tall is the radio tower?
A) 7.48 meters
B) 10.77 meters
C) 7.61 meters
D) 21.17 meters