She is a cute, quiet girl. As a daughter, she has no secrets from her mother, who is very pleased with her. But recently she has become somewhat mysterious, not so open as before. She has a diary that she keeps under lock and key. Her mother cannot help worrying about her: what if she falls in love, which is too early for a girl of her age. After all, she is reaching the "dangerous stage". These thoughts have caused trouble in the mother's mind.     One weekend the girl came to tell her mother that she was going to the cinema with her schoolmate and would return late. This was the first time her mother agreed, and she couldn't help worrying because her daughter had never been away at night before. The mother waited till nine and her uneasiness got the upper hand over her. She decided to go out to meet her daughter. Just at that moment the noise of a car pulling up drew her to the window and - there was her daughter, waving goodbye to a boy. Her heart missed a beat. When the girl came in, the mother was watching TV, pretending nothing had happened."Mum, I'm back." "Yeah." "Sorry to be late. Still sitting up?" "Yes, Oh, that... Who's that boy?" The daughter was stunned   for a moment. "Ah. It's my monitor. He gave a lift on his way home. Mum, I'm going to bed." "All right. Go to sleep early."  Next morning when the mother went to the daughter's room to do some tidying, she found her diary left at her pillow. After a few minutes' hesitation she eventually opened it to the entry of the night before. It reads: Mum, it's love that made you ask, but it would show your understanding of me if you hadn't.  Holding the diary, the mother fell in thought. Which of the following is TRUE according to the story?
The girl knew her mother would ask her the question about the boy. What the daughter did recently worried her mother. The mother was eager to read her daughter's diary the next day. The girl's diary was always unlocked.