What Was the Major Cause of the East St

What was the major cause of the East St.Louis riot in 1917?

A) Racial tension over employment in a defense factory sparked the riot.
B) A white man was accused of murdering an African American child.
C) An African American was accused of rape.
D) There was a misunderstanding of the homeowners' restrictive clauses.
E) Black members of the National Guard were told to not wear their uniforms.