I think the answer is D.) To fly
I searched what infinitive means and this is what I got.
She is initially horrified at the idea of going to the ball. Her husband knew that she was interested in being a part of the upper class and taking part in their activities. When he came home with the invitation to the ball, he thought his wife would be pleased. She was not. She did not feel she had anything suitable to wear to the ball and therefore was unable to go.
The sentence that contains an infinitive phrase is A) He visited Congress to gather support for his proposal.
The infinitive phrase is <em>to gather.</em>
Going to a flight school or learning how to fly is not easy and neither cheap. The students should go to a training of at least 40 hours. Although the course or journey of the students is hard, it is satisfying to see them know and develop knowledge and skills in aeronautical field.
