From the top of a lighthouse 70 m high with its base at sea level, the angle of depression of a boat is 15°. The distance of the boat from the foot of lighthouse is
1
\(50\;\left( {2 + \sqrt 3 } \right)\)
2
3
\(40\;\left( {2 + \sqrt 3 } \right)\)
4
\(60\;\left( {2 + \sqrt 3 } \right)\)