For any two events $A$ and $B$, $P(A)=P(A|B)=1/4$ and $P(B|A)=1/2$. Then which of the following is NOT correct?

Given $P(A)=P(A|B)=1/4$. Since $P(A|B)=P(A)$, events $A$ and $B$ are independent.This also means $P(B|A)=P(B)$, so $P(B)=1/2$.$P(\bar{A}|B)=1-P(A|B)=1-1/4=3/4$. (Correct)Since $A,B$ are independent, $\bar{A},\bar{B}$ are also independent.$P(\bar{B}|\bar{A})=P(\bar{B})=1-P(B)=1-1/2=1/2$. (Correct)$P(A\cap B)=P(A)\cdot P(B)=(1/4)\cdot (1/2)=1/8$. (Correct)$P(A\cup B)=P(A)+P(B)-P(A\cap B)=1/4+1/2-1/8=2/8+4/8-1/8=5/8$.Option C says $P(A\cup B)=3/4$, which is $6/8$. This is NOT correct.