The correct answer is B: Ravi can't marry as Rama is still alive.

The legal principle states that whoever, having a husband or wife living, marries again is guilty of bigamy. In this case, Ravi and Rama were married in 1994. Rama was unable to attend marital duties due to illness, and with her consent, Ravi married Kiran.

However, even with Rama's consent, Ravi's marriage to Kiran still constitutes bigamy under the legal principle as Rama is still alive. Ravi's second marriage is invalid and he cannot legally marry another person as long as his first wife is alive.

Therefore, the correct decision in this case is B: Ravi can't marry as Rama is still alive. Ravi's actions constitute an offense of bigamy, even with Rama's consent.