If P(A∣B)=0.5P(A|B) = 0.5P(A∣B)=0.5, P(B∣A)=0.25P(B|A) = 0.25P(B∣A)=0.25, and P(A)=0.4P(A) = 0.4P(A)=0.4, what is P(B)P(B)P(B)?
0.1
0.2
0.4
0.8