41. During a competition, a swimmer will be swimming the width of a river, from X to Y in the figure below. The swimmer wants to know how wide the river is. The right triangle shows the measurements the swimmer obtained by walking 100 feet from X to Z, sighting to Y from both points. From this sighting, it is determined that the measure of ∠Z is 40°. How wide, in feet, is the river?

A.

B.