Answer:
O1) He worked tirelessly as a lawyer for the NAACP for nearly a decade to desegregate public facilities in Mississippi.
Explanation:
Medgar Evers was a World War II veteran who would become an integral part of the Civil Rights Act. He was also responsible for most of the desegregation acts of the American society/ government and also helped in the integration of the University of Mississippi.
Among the given options, Medgar Evers was involved in all of them except that he worked as a lawyer for the NAACP for a decade. Contrary to that, he was the organization's first field secretary in the southern state of Mississippi.
Thus, the correct answer is option 1.