The "Panic Begins" for Many Middle-Aged Americans Regarding the Thought

Multiple Choice

The "panic begins" for many middle-aged Americans regarding the thought of death.Which is/are correct reason(s) for this?

A) realization that the remaining years of life are fewer than those already lived
B) realization that after one's parents are dead, the "buffer zone" is gone
C) if one's job depends on physical vigor, he/she begins to realize that he/she is not getting stronger
D) all of the above are correct
E) only a and b of the above are correct