Answer:
D
Explanation:
When we rotate this around the line m, we will get something that looks like half of a sphere, which is also called a semisphere. So, eliminate answers A, B, and E.
Now, we look at the radius. When we rotate the shape, the surface looks like a circle. The radius doesn't change, though; it is still 5. This means that the diameter, which is 2 times the radius, is 5 * 2 = 10 units.
Thus, the answer is D.
Hope this helps!