At times worrying is a normal response to a difficult event or situation – a loved one

问题补充：

At times, worrying is a normal, response to a difficult event or situation – a loved one being injured in an accident, for example.

A. effective

B. individual

C. inevitable

D. unfavorable

答案：

A. effective

B. individual

(答案→)C. inevitable

D. unfavorable

解析：考查词义辨析。 effective ，有效的，individual个人的，inevitable不可避免的，unfavorable不支持的，根据句意担忧是一种正常的，不可避免的反应。故选C。