Hi, I'm having a hard time on this question. I can see why E is right, but I can't see why B is wrong. If U is first, that does this U_ _ _ | _ And if U is in, that means that R cannot be 2nd, and if R can't be 2nd, and S can't be 1st (U is there,) 2nd (rule two), 3rd (if it goes 3rd, there's no pla...