Two events AAA and BBB satisfy P(A)=0.4,P(B)=0.5,P(A∪B)=0.7P(A)=0.4, P(B)=0.5, P(A \cup B)=0.7P(A)=0.4,P(B)=0.5,P(A∪B)=0.7. What is P(Ac∣Bc)P(A^c | B^c)P(Ac∣Bc)?
0.2
0.4
0.6
0.8