Answer:
Roosevelt includes the second paragraph to serve as a rebuttal for the following counterclaim:
D. A world free from fear is not possible in the near future.
Step-by-step explanation:
In the first paragraph of the excerpt, Roosevelt speaks of "freedom from fear" and explains that it refers to the safety one feels when one knows there aren't enough weapons in any country for an attack to happen. Simply put, it would be the reduction of the production and possession of weapons, which would ensure no more wars would happen.
The second paragraph of the excerpt serves to rebut a possible counterclaim. The very first sentence reveals what it is: "That is no vision of a distant millennium." Roosevelt is answering the possible counterclaim that such a freedom cannot be achieved in the near future. According to him, it is possible to be attained "in our own time and generation." Therefore, letter D is the best option:
"D. A world free from fear is not possible in the near future" is the counterclaim being rebutted.