What is the difference between a claim and a thesis statement?

Claims sometimes stand alone and at other times are part of a series (of claims and subclaims). In effect, the "thesis" of a work or part of a work is a kind of claim (we might say that the overall thesis is the "main claim"). It is important that you know when are making claims and what kinds of claims you are making.

i think its d, but grammarly says none

explanation:

from the political point of view it could be said that the candidate   is an effective speaker because she takes a strong position on the issue. it is an open discussion but probably she is making a presentation and can choose which subjects she wants to address. she is very likely to attain her aim which is to convince voters to accept her proposal.