In terms of types of sleep problems, older people are more likely to complain of________ while younger people complain more about____________

a. waking frequently during the night; taking too long to get to sleep
b. taking too long to get to sleep; waking frequently during the night
c. aches and pains while they sleep; having too much wakeful energy at bedtime
d. needing to go to the bathroom during the night; sleeping too long and too soundly

A