Answer: The right answer is the A) Compelled.
Explanation: Just to elaborate a little on the answer, it can be added that the word compel comes from the Latin verb compellĕre, which can be translated as "to obligue." The speaker is recalling that she empathized with the children for a while, but she thought differently when she had to look after them when they were sick. She helped one of them in particular, who did not seem to know or to notice that, despite her attentions, she was forced to care for him.