'A' agrees to sell and deliver 25 tins of oil to 'B' at a particular rate on 1st June 2022. He also…

Under Order I Rule 1 of the Code of Civil Procedure, 1908, multiple persons may be joined in one suit as plaintiffs only where any right to relief in respect of, or arising out of, the same act or transaction or series of acts or transactions is alleged to exist in such persons, and where, if they brought separate suits, any common question of law or fact would arise. Because A entered into two distinct contracts with B and C independently, the claims do not arise out of the same transaction, so "B & C cannot join as plaintiffs in suit against A as the transactions are different." is correct.