A warm-hearted (热心的) nurse on her first day’s work went near to a patient. He has come to London as a tourist. She asked him if she could do something for him, but he only waved (摇) his hand and said something she could not understand. With a smile, she asked him again and he just kept saying the same word but in a much lower voice before closing his eyes. She went to the doctor and repeated (重复) to him the sounds she had heard. "My dear girl, " said the doctor after listening carefully to what she repeated, he was saying, "You are standing on my oxygen pipe (氧气管)!\ What do you think of the nurse in the story She is ______.
A．warm-hearted and strict in her work B．a new hand and not careful enough C．good at her work