The correct option is A both (a) and (b)
As per Section 34 of the Act, grounds for application to set aside the arbitral award has been provided. But there are certain unstated grounds of setting aside the awards such as any misconduct in proceedings of arbitration. Such misconducts in proceedings include any arbitral proceedings is carried on ex-parte i.e. without party or parties without any sufficient cause to the same. Also in case if evidence was rejected in improper manner, it amounts to misconduct of proceedings.