Explanation
Finite set: A set is said to be a finite set if it is either a void set or the process of counting elements surely comes to an end is called a finite set.
For a universal set
[tex]n(A\text{ u B\rparen = n\lparen A\rparen +n \lparen B\rparen +n \lparen A n B\rparen}[/tex]Thus, if we have
[tex]n\left(AuB\right)=n\left(A\right)+n\left(B\right)[/tex]Then it means that
[tex]A∩B=Ø[/tex]Hence, option B is correct
