The goal of designing a text or speech for the audience is to be well understood, convince them with your arguments, to entertain and keep them interested in the topic.
When an author develops a text or speech, it can come with new ideas, that may clash with the audience's ones. Bringing new thoughts and argumentation might incite critical thinking and change of minds; It is not necessarily ideal for the author to match the audience's opinions.
So, a. to make their own opinions closer to the audience's opinions is NOT a reason the authors consider the audience when crafting their texts or speeches.