As the organization determines which customers to serve, it must first divide the market into reachable portions, or of the market, and then select which portion of the market to target.

answer; i do believe its (b) 12.5 years of age;

"harry t. moore (1905-1951) – civil rights activist, leader, and the first martyr of the civil rights movement. fannie lou hamer (1917–1977) – leader in the american civil rights movement; co-founder of the national women's political caucus and freedom democratic party. james farmer (1920–1999) – congress of racial equality."