Answer:
A - direct example of his writing
Step-by-step explanation:
A primary source is anything that is a first-hand account of what happened (i.e. original writing, photographs, etc.). Of the answers listed, A is the only one that could possibly refer to a primary source because it mentions that this is a direct sample of his writing.
Evidence, interpretation, or reposts on a website are all secondary sources. The people who wrote them weren't there when this happened.