Many Psychologists Are Concerned About Whether Certain Aspects of Development

Many psychologists are concerned about whether certain aspects of development are marked by universality or diversity. Which one of the following statements illustrates diversity?

A) Children almost always first sit, then walk, then run.
B) Children think in increasingly logical ways as they get older.
C) By interacting with their physical environment all children learn that things always fall down, never up, when released.
D) On average, teenagers who live in middle-income neighborhoods have better study skills than those who live in low-income neighborhoods.