"Thirty-One Men Were Arrested and Thrown in Jail as 'Conspirators

"Thirty-one men were arrested and thrown in jail as 'conspirators,' although they all declared more than once they did not know they were firing on officers.Excitement was at fever heat until the morning papers,two days after,announced that the wounded deputy sheriffs were out of danger.This hindered rather than helped the plans of the whites.There was no law on the statute books which would execute an Afro-American for wounding a white man,but the 'unwritten law' did.Three of these men,the president,the manager and the clerk of the grocery-'the leaders of the conspiracy'-were secretly taken from jail and lynched in a shockingly brutal manner.'The Negroes are getting too independent,' they say 'we must teach them a lesson.'" What "unwritten law" was Ida B.Wells referring to in this 1892 editorial?

A) That blacks had to serve whites
B) That whites had the right to kill blacks who wounded whites
C) That black men were not allowed to speak to white women
D) That white officers did not have to protect black neighborhoods