qwer: 3

Answer 1

$\bar{B}=\{s,t,u,v,w,x,y,z\}-\{u,v,w,x\} = \{s,t,y,z\}$

$(A\cup\bar{B})=\{s,t,x,y,z\}$

$(A\cap B)=\{x\}$

$(A\cup \bar{B})\cap(A\cap B)=\{s,t,x,y,z\}\cap\{x\}=\{x\}$

But there was no such option.