You need a colon and period in your sentence.
A leader so your answer would be c
What would happen to writing if paragraphs didn't exist is that when the reader reads the writing, he/she might skip a sentence or even get confused. And then you might not understand it yourself. It can affect the reader by not understanding what is going on in the writing if it's a story.
Answer:
left
Explanation:
Because its the past tense.
Hope this helps:)