What about 14?

[v0031]

A little girl thought she was not as beautiful as other girls, and nobody liked her. So she was __1__happy. She always stayed at home by herself and didn't talk to __2__.
One day, her mother gave her a beautiful hair clip. When she __3__ it, she looked much more beautiful than before. She decided to go to school in the beautiful hair clip.
On her way to __4__ she found that everyone who saw her smiled at her. Most of her schoolmates said hello to her, __5__ this never happened before. She thought that the beautiful hair clip __6__ them all to her. She was so happy about all of the wonderful __7__.
Though all her classmates wanted to know __8__ happened to her, she didn't want to tell __9__ about her beautiful hair clip.
When she went back home after school, her mother asked her, “Did you know you __10__ your hair clip at home? I found it by the door this morning.”
She was __11__ to hear what her mother said. She understood that she didn't wear the hair clip __12__ school at all.
It's not important what we wear or how we __13__. The most important thing is __14__ we think about ourselves. __15__ we want to do a thing successfully, first try to be confident. If we think we can, we can.
 (　　)14.A.what         B．how             C．who           D．why

I go for how. Do you think so?