A family consists of seven members I, J, K, L, M, N, There are three married couples. J is an engineer and father of M. N is grandfather of M and is a contractor. K is daughter-in-law of L who is a nurse by occupation, O is M?s uncle who is a professor. There is one student, one housewife and one doctor in the family. The student is unmarried and K is the sister-in-law of J. Which of the following are married couples?

• A. \[\text{IN},\text{ JK},\text{ NL}\] 
• B.  \[\text{OM},\text{ IJ},\text{ NL}\]
• C.  12   
• D.  None of these