1. How did A married B? Was it a marriage conducted at a temple? Were there guests and/or witnesses? Can A collect a temple certificate or certificate from the priest that A had married B? If there is no evidence that A had married B then it will be difficult for A to prove that a and B are married couple.
2. If A can prove that he had married B then his marriage with C becomes illegal and invalid and he will be leveled with charge of bigamy punishable with jail term.
3. If A's marriage with B can not be proved with evidence then there arises no question of getting divorce from B.
4. In the said event, A can file a divorce petition against C on te ground of cruelty or negotiate with her to agree for a MCD which will be decided with in 6 & 1/2 months from the date of its filing.
5. Even if A can prove with evidence that he has married B, it will not be possible for him to get back B if B does not want to come back to A.
6. However, B will make another mistake to marry X without taking decree of divorce from A, if her marriage with A can be established with evidence and in that case B's marriage with X will be illegal hence invalid.