Alright, lets get started.
Please refer the attached diagram.
The roof will make a right angle triangle.
Thy hypotenuse of the triangle will be the length of roof that is given 44 feet.
The opposite side will be height of roof that is 10 feet.
Lets suppose roof makes x degree angle from horizontal.
So, we know,
sin x = opposite / hypotenuse
sin x = 10 / 44
sin x = 0.2272727272
Taking inverse on both sides
sin -1 (sin x) = sin -1 (0.2272727272)
x = sin -1 (0.2272727272)
x = 13.13 degrees
So the angle that roof makes with horizontal is 13.1 degrees (option b) : Answer
Hope it will help :)