Until Recently, Developmental Scientists Ignored Middle Adulthood

Until recently, developmental scientists ignored middle adulthood. Now, however, they're beginning to study it. Why?

A) Because middle adulthood is a time when there are great changes in the body and mind.
B) Because today's middle adulthood is equivalent to the young adulthood of the past.
C) Because they realize that the other stages have been overstudied.
D) Because all the Baby Boomers have now reached middle adulthood.