Daryn and Marco Are Both Three Years Old

Multiple Choice

Daryn and Marco are both three years old. Daryn seems more coordinated than Marco, and Marco's speech is more advanced than Daryn's. What principle of development does this represent?

A) All areas of development are interrelated.
B) There are optimal periods of growth and development.
C) Development has cumulative and delayed effects.
D) Rates of development vary.
E) There are developmental tasks throughout life.