Answer:
A). To reinforce the primary claim.
Step-by-step explanation:
An impressive conclusion is primarily inclined towards restating the central claim or argument(as described in the thesis statement) in order to 'reinforce the primary/central claim' on the readers and persuade them(through sufficient evidences) to believe in it. Such conclusion is not merely the 'sum-up' of the essay or paper that offers a 'sense of closure' but it also proposes some concluding remarks along with the brief restatement of key points that leaves the readers with a 'take away'(as the author intended) from the essay or paper. Thus, option A is the correct answer.