I need help on this question

It is 4.7 km from Lighthouse A to Port B. The bearing of the port from the lighthouse is N73E. Aship has sailed due west from the port and its bearing from the lighthouse is N31 E. How far has the ship sailed from the port? Round your answer to the nearest 0.1 km. 0 A. 3.1 km 0 B. 3.5 km 0 C. 3.7 km 0 D. 2.7 km