Explanation:

- Section 497, IPC defines adultery as involving sexual intercourse with a person known or believed to be someone else’s wife.

- The key element or actus reus here is about the person involved—specifically, she must be the wife of another man.

- Option 1: Time — The law doesn't specify a particular time; time isn’t the main factor.

- Option 2: Place — Where the act occurs is not central to the actus reus in this section.

- Option 3: Person — The actus reus is about engaging in intercourse with a specific person: the wife of someone else.

- Option 4: Married woman — The woman's marital status is important, but the essential actus reus relates to the "person" as the wife of another, making “person” the broader and precise basis.