Answer:
The correct answer is: C. they help the reader make connections between ideas.
Explanation:
Transitional words, phrases and clauses are used to connect other words, phrases and clauses (generally, ideas).<u> They help the reader to make a connection between ideas and they make the narrative logic and understandable. </u>
There are many types of transitional words. Some of them are:
contrast: however
example: for instance
addition: not to mention
similarity: likewise
etc.
All the other options (A, B, D) are correct, but they are just part of the response C. Transitional words do introduce the story, do help make good conclusions and do clarify the things, but all these are IDEAS that need to be connected and explained.
