A plane flying a straight course observes a mountain at a bearing of 30 2 to the right of its course. At that time the plane is 8 kilometers from the mountain. A short time later, the bearing to the mountain becomes 40.2. How far is the plane from the mountain when the second bearing is taken to the nearest tenth of a km)? OA. 10.3 km OB. 6.2 km OC. 11.7 km OD. 4.2 km