It’s gotta be B, the other answers make sense while that one doesn’t at all...
Yes it is, all can be just worded correctly. Hope this helps!
The correct answer is A. reliable.
The writer was 'an authoritative source' because of her degrees, guest appearances, etc. Thus, she was a source you could rely on, she was reliable, given that she had experience to back her ideas up. Therefore A is the only correct answer.
