One evening, the telephone rang while the old woman was preparing supper. She went to answer it. She was told that one of her sons died in a traffic accident- She heard this and fell in a faint (晕倒). When she came back to life, she was in hospital. And she needed to be helped after that.
Several months later she was told on the telephone her daughter died while she was being operated on. The old woman was so sad that she had to be in hospital again. From then on she was afraid to answer any telephones and sometimes she was afraid to hear the bell. Of course it brought them some trouble and some important business was held up(耽误). So her husband advised her to see a psychiatrist(精神病医生). The man examined her carefully and then asked her some questions.
"You'll soon be all right if you follow my advice, Mrs. Keller, "said the psychiatrist.
The old woman took the medicine the doctor gave on time and tried to forget her dead son and daughter. And two months later she went to see the psychiatrist again.
"You've saved me, Doctor, "the old woman said, as soon as she saw him,
"Are you afraid to answer the telephones now？"
"No," answered Mrs. Keller. "I dare(敢)answer it whether it rings or not!"
Mrs. Keller could do all housework because ______.

A. she had no money to employ a helper
B. she was strong enough to do all at home
C. she-didn't believe anybody
D. only she was free at home