[单项选择]

When John Weston awoke that morning, he remembered that his mother was going into hospital. He hadn’t worked out what was wrong with her. He knew, though, she hadn’t been well for some time now, and it bad become familiar to him to see her eyes narrowed in a sudden attack of pain, and her hand pressing against her heart. Their own doctor, who she had finally gone to for advice, had sent her to a specialist who knew all about these things. He had told her that just as soon as there was a bed for her, she would have to come into his hospital where he could look after her himself.
During the weeks since then the pains had come ever more frequently, and the narrowed eyes be came an almost lasting part of her expression. Always rather sharp, she began losing her temper over little things so that John’s father kept his thoughts to himself more and more. John, as ready as possible to make allowances (体谅), tried to think what it would be like to have toothache a
A. as soon as she realized that something was wrong
B. only after her husband advised her to
C. a long time after the trouble began
D. when John asked what was wrong with her