单项选择题

Psychologically there are two dangers to be guarded against in old age. One of these is too great an absorption in the past.()

A. It is dangerous for old people not to face the harsh reality.
B. It is dangerous for old people to look back on their past glories.
C. One of the dangers is being interested in the present, not in the past.
D. One of the dangers is living in memories, in regrets for the good old days.