Which of the Following Statements About the Timing and Variations

Which of the following statements about the timing and variations in puberty is TRUE?

A) Children in European countries mature up to a year earlier than their American counterparts.
B) For girls,menarche is considered within the normal range if it appears between the ages of 9 and 15.
C) Genes have little to do with when and how puberty develops.
D) Non-Latino white girls experience puberty earlier than African-American girls.