The angles of depression of two ships from the top of a light house are 45° and 30° towards east. If the ships are 100 m apart, the height of the light house is

• A. $\frac{{50}}{{\sqrt 3+ 1}}m$$
• B. $\frac{{50}}{{\sqrt 3- 1}}m$$
• C. $50\left( {\sqrt 3- 1} \right)m$$
• D. $50\left( {\sqrt 3+ 1} \right)m$$