A and B are summits of two mountains rise from a horizontal plain. B being 1200m above the pain. Find the height of A, it being given that its angle of elevation as seen from a point C in the plain (in the same vertical plane with A and B) is 50 deg, while the angle of depression of C viewed from B is 28°58' and the angle subtended at B by AC is 50 deg.

A. 2847.64 m

C. 2989.42 m

B. 3200.20 m

D. 3002.33 m