Which Statement About Income Distribution in the United States Is

Which statement about income distribution in the United States is true?

A) The income gap between the richest and the poorest segments of the population has declined over the past 20 years.
B) The income gap between the richest and poorest segments of the population has increased over the past 20 years.
C) The income distribution gap has not been measured.
D) The income gap had been increasing,but has declined over the past decade.