Which action did Lonnie Smith take to advance the cause of civil rights for African Americans in Texas?

A. he refused to take a seat in the backs of a city bus

B. he petitioned the governor for the right to attend University of Texas

C. he published articles highlighting racism and the state government

D. he filed a lawsuit challenging the races primary system used by democrats

D. Lonnie Smith filed a challenging lawsuit to primary system of races used by democrats to advance the cause of civil rights for African Americans in Texas.

Explanation:

Lonnie Smith, a dentist by profession, was closely associated with the civil rights movement in Texas and was also a part of the National Association for the Advancement of Colored People. It was he who raised his voice against the all-white primaries in Texas and filed a lawsuit in the Supreme Court.

It was after the Supreme Court passed the judgment in the favor of Lonnie Smith the blacks got the right to vote in Texas.

The correct answer is D. he filed a lawsuit challenging the races primary system used by democrats.

In 1940, he tried to vote but he was denied his right, he filed a lawsuit and since 1944 he was able to vote in the same place where he was once refused.