Where are the following to choose
A. Somewhat. The sentence still makes sense without it, and it doesn't matter how skeptical she is since she's still doing research either way, so it can be cut out.
The main verb would be "indicated", being that "research" (which is the main subject) is what's doing the action, which is indicating.
The whole sentence is basically about the research indicating... etc.
I will leave the answer is C. The person who wrote the paragraph used a personal example, but personal example did not help.