Explanation:

- Section 21: Deals with the objections to the place of suing. It states that objections regarding jurisdiction must be raised at the earliest possible stage in the Court of the first instance. If not raised timely, they may not be considered later.

- Section 22: Pertains to the power of transfer of cases by the High Court or the District Court for the convenience of parties or witnesses.

- Section 21A: A less common section, which, if referred to, generally deals with specific legal provisions that may not be present in every jurisdiction.

- Section 20: Discusses the territorial jurisdiction of a court where the defendant or any of the defendants resides or where the cause of action arises.

Correct Answer: Section 21