Explanation:

- Option 1: A withdrawal of suit

- When a suit is withdrawn, it typically doesn't operate as res judicata because the case wasn't fully decided on its merits. Res judicata requires a definitive decision.

- Option 2: An exparte decree

- An exparte decree is passed in the absence of one party. It can operate as res judicata because it is a final decision unless set aside.

- Correct Answer

- Option 3: A compromise decree

- A compromise decree operates as res judicata since it is a final resolution agreed upon by both parties. Both parties accept its terms as binding.

- Option 4: None of the above

- This option isn’t accurate because both exparte decrees and compromise decrees can operate as res judicata.