In a certain code language,
A + B means 'A is the mother of B'
A - B means 'A is the brother of B'
A × B means 'A is the wife of B'
A ÷ B means 'A is the father of B'
Based on the above, how is M related to O if 'K ÷ L × M - N + O'?
1
Mother's husband
2
Mother's brother
3
Wife's father
4
Daughter's husband