The correct option is D Polk was born in Mecklenburg, North Carolina, in 1795 as the oldest of 10 children.
The second paragraph gives us the biography of Polk. This follows the first paragraph which introduces us to the central theme of the passage - James Polk. In the structure of the paragraph it is logical that the Polk's biography makes up the second paragraph. However, options A and B do not fit here as they are superfluous information with respect to the context of the passage and do not matter in the end. Option C does not fit here as its logical to start with the very basics like birth date and place, whom he marries does not come until later, if at all. So, option D best befits the context.