The Bush and Kerry campaigns exchanged attacks regarding______.

A．questioning the assumption behind certain experiments involving children under the age of 15
B．describing the new scientific findings about high blood pressure and suggesting some implications
C．describing two different methods for studying the causes of high blood pressure
D．revealing a discrepancy between the findings of epidemiological studies and laboratory studies on essential hypertension

A．The history of Black People in the United States.
B．West African Tribal Relations.
C．The Origin of Modern Afro-American Consciousness.
D．Slavery: A Democratic Anomaly.