How many African Americans had served in the U.S.Senate throughout American history before Barack Obama took his seat there in 2005?

A) 1
B) 4
C) 8
D) 13

African Americans

A demographic group in the United States with ancestors who were brought from Africa during the transatlantic slave trades and their descendants.

U.S. Senate

One of the two chambers of the United States Congress, comprising senators from each state, tasked with making and passing federal laws.