Explanation:

- Option 1: Order 10, Rule 2 - This rule in the Code of Civil Procedure covers the oral examination of a party or their companion. It allows the court to ascertain matters in dispute by questioning the parties.

- Option 2: Order 4, Rule 13 - Deals with the institution of suits but is not directly related to the oral examination of parties.

- Option 3: Order 6, Rule 10 - Concerns the presentation and pleadings in a suit. It doesn't pertain to oral examination.

- Option 4: Order 3, Rule 22 - Relates to appearances and agents of parties. It doesn't address oral examination.

Option 1: Order 10, Rule 2 is the correct choice.