Could you help me with the question？

Choose a correct answer and explain why:

Rowling had an idea for a story about a boy wizard. She outlined the story on the train and continued to work on it _____ (and/until)eventually it came the first Harry Potter novel.

Correct the article under and explain why:

I flew home to take care of my elderly mother who had just received an operation. I was terrified of flying so I had taken some pills to help me get through the trip. When I was half asleep, the high school boy sitting next to me ordered a breakfast sandwich. However, when the flight attendant said, "credit cards only," he replied it, "Oh, sorry."

Hearing their conversation, i immediately woke up and said, "I've got it" At first he wanted to refuse. However, at my insistence he finally accepted my help. I was very happy to help him out.