What is the minor subject of the person born in March?

A was born in September and has Hindi major. So, either A is the oldest or the oldest person was born in January. If a student is in 2nd semester, his minor has to be Commerce. According to condition (iv), A has Commerce and Biology as his minors. Case 1: The oldest was born in January. Only the youngest person is in 4th semester and two persons each are in the other semesters. Both the oldest friends are in 2nd semester but have different majors. J was born in the immediate month before K. L was born after J. J is senior to K but not immediately. So, K must be in 1st semester and J in 3rd semester. So, J's major and minor will be History and English just like L. K has English major. But K was born after December. So, case 1(I) is invalid. B was born in October. C has Biology major and is junior to A. C was born after A. So, C must be in 1st semester. C has Biology major and is junior to A. C was born after A. So, C is in 1st semester and M in 4th. According to condition (I), we get C's minors as: So, L is in 3rd semester. Now from the conditions, only students having major Science or Hindi can have Commerce minor. As the 2nd semester students have different majors, so B must have Science as major. The one born in October has the same major as M.