Answer:
D. 
Step-by-step explanation:
Please find the attachment.
Let x be the angle of depression.
We have been given that the look out point of a lighthouse is 30 feet above sea level. A boat is 20 feet away from the base of the lighthouse.
Upon looking at our attachment we can see that the lighthouse and boat forms a right triangle with respect to sea level.
We will use tangent to solve for the angle of depression as tangent relates the opposite side of a right triangle with adjacent.



Using arctan we will get,


Therefore, the angle of depression fro the look out point to the boat in the water is 56 degrees and option D is the correct choice.