An aeroplane fl ying at a height of 300 m above the ground passes vertically above a plane at an instant when the angle of elevation of two planes from the same point on the ground are 60° and 45° respectively. What is the height of lower plane from ground ?

• A. 500 m
• B. 100 √3 m
• C. 500 √3 m
• D. 15 \((\sqrt 3 +1)\)m