Four students Alpana, Behram, Ramesh and Doug joined a college in 1991, 1992, 1993 and 1994 but not necessarily in that order. Each student joined one of the four departments, viz. Physics, Chemistry, Mathematics and Biology. No two students joined the same department. One of those who joined the college before 1993 joined Chemistry. No one joined the college after Ramesh. Doug joined Physics. Alpana joined one year after Doug but didn't join Chemistry. Then Behram joined the college in the year

Correct option is A

Given:
Four students: Alpana, Behram, Ramesh, Doug
Years: 1991, 1992, 1993, 1994 (one each)
Departments: Physics, Chemistry, Mathematics, Biology (one each)
Clues:
One of those who joined before 1993 joined Chemistry.
No one joined after Ramesh → So Ramesh joined in 1994
Doug joined Physics
Alpana joined one year after Doug
Alpana did not join Chemistry

Solution:

Doug = 1992 → Alpana = 1993

Ramesh = 1994
→ Behram = 1991
Now assign:
Doug → 1992
Alpana → 1993
Ramesh → 1994
Behram → 1991 
Now check clue:
One of those who joined before 1993 joined Chemistry
→ Before 1993: Behram (1991), Doug (1992)
Doug = Physics (given) → so not Chemistry
→ Behram must be the one who joined Chemistry 
Also:
Alpana ≠ Chemistry 
Ramesh is in 1994 (latest) 

Final Answer: (A) 1991