The correct answer to this open question is the following.
Although there are no options attached, we can say the following.
W.E.B Dubois could prove that these Jim Crow laws were illegal and should not be allowed in court in that these ideas of "separated but equal" were against the principle of the "Emancipation Declaration" established by the United States President Abraham Lincoln on January 1, 1863.
As the great activist and man of principles he was, W.E.B. Du Bois (1868-1963) could have proved in court that the Emancipation Declaration and the Presidential opportunity granted to the southern states to do Reconstruction at their own pace, must guarantee the respect for the civil rights of the African American people.
W.E.B. Du Bois had a major influence on the ideas of civil rights in his time and formed the National Association for teh Advancement of Colored People.