HaileyS0922,
The answer is the second option "The Due Process Clause." The Due Process Clause was when every person deserved a free trial but the fourteenth amendment ratified it stating "deprived of life, liberty or property without due process of law" and then making it a legal obligation for all states.
Hope this helps!
 
        
             
        
        
        
I would go with Brown v Board of Education. It gave more rights to African Americans and made them one step closer into beating segregation. Through the court case, segregation in schools was deemed unconstitutional, and so was segregation in other public places.