Explanation:

- Option 1: The restitution sought must be in respect of the decree or order which had been varied or reversed.

This means that the reversal or variation should directly relate to the decree or order for which restitution is being sought.

- Option 2: The party applying for restitution must be entitled to a benefit under a reversing decree or order.

This implies that the party seeking restitution should have gained something from the subsequent decree or order that reverses or varies the original.

- Option 3: The relief claimed must be properly consequential on the reversal or variation of the decree or order.

This suggests that the relief must directly result from the reversal or variation, forming a logical consequence.

- Option 4: All of these

For s. 144 to apply, all these conditions should be met.