Which action was not used by some white southerners to deny justice to blacks?

a. they passed black codes.
b. they allowed hate groups such as the ku klux klan to terrorize blacks.
c. they refused to establish schools for blacks.
d. they allowed blacks to vote and hold political office.

this question really stumped me..

Which of the following best describes how the texas constitution of 1876 has changed since its enactment? there has been only one major overhaul. there have been several major overhauls. the constitution has undergone piecemeal revision. the constitution has doubled in size nearly every year since its enactment. the constitution has remained essentially unchanged from when it was first enacted.