The life stage in the life course in which an individual begins to reorient his or her thinking from the time since to the time left to live is a) young adulthood b) the early middle years c) the late middle years d) the older years

The correct answer is C.

To reorient the thinking process means to change one's view or perspective. Here, we are talking about the time scales, numbers of years left to live. This usually happens in the late middle years as the getting older process becomes more apparent and visible.

In young adulthood and early middle years people dismiss old age as something far away. They are usually healthy and productive so they don't think about death and remaining years a lot. Old or very old people are usually resigned to their destiny by then, and they accept the fact that they will die soon.

An individual begins to reorient his or her thinking regarding years left to live in the late middle years. He or she knows that they are not young any longer and that they time on earth is limited. Some of them may start to panic, fearing they have not meny years left to do what they want to do in life (midlife crisis).  For others, this realization may be a motivation to change their life (the so called last chance) or to reflect on the passage of time.

allusion   is the right answer