A. An encyclopedia article about the history of NASA and its accomplishments.
Explanation:
This is the source that would provide the best and most credible support for this claim. Our purpose is to demonstrate that NASA deserves to survive as an institution. In order to do so, we need to demonstrate that NASA's accomplishments throughout its existence have been significant. The encyclopedia article can best help us prove it.
The last sentence “I was not conscious after my head hit the ground.” Is the correct answer. The person was “not aware” or knocked out after hitting their head.
