Classification systems used to divide all humans into specific racial categories are based on

• A. Objective genetic differences
• B. Geographic ancestry
• C. Social meanings given to biological traits
• D. Natural selection gradients

Answer: (C)

Racial classification systems are built from social meanings attached to biological traits rather than from clear biological boundaries. Societies decide what traits matter (often skin color, hair texture, facial features) and assign social significance to them, which then creates distinct racial categories. Genetic variation in humans is continuous and overlapped, with much variation found within any so-called group and no single genome defining a race. This shows that race is not a fixed biological fact but a social label shaped by culture and history. Geographic ancestry or evolutionary differences may influence appearance or traits, but they do not provide the basis for racial categories as they’re used in society.