A 24-ft ladder leans against the outside wall of a school, waiting for someone to climb and fix a broken window. The base of the ladder is 15 ft from the base of the building. Before Levi climbs the ladder, he wants to make sure he has the ladder at a safe angle with the building before climbing. Find the angle of elevation the ladder makes with the ground.
a. approx. 51.3°
b. approx. 32.0°
c. approx. 38.7°
d. approx. 58.0°