You have not provided the options, but I can answer your question nonetheless.
The term that refers to the smooth flow of ideas in sentences, between paragraphs, and in paragraphs is coherence. When something is coherent, all of its parts are well-connected. This characteristic of a piece of writing is crucial because, otherwise, we wouldn't be able to understand it. Words in sentences need to be connected in a way that makes sense. The same applies to the sentences that make up paragraphs, and paragraphs that make up an entire text.
