Explanation:

- Option 1: should remain intact

- Quantum Meruit does not apply when the original contract remains intact. It typically arises when the contract cannot be completed as agreed.

- Option 2: must be discharged

- Quantum Meruit claims are often made when a contract is discharged due to a breach, invalidation, or other reasons that prevent full execution.

- Correct Answer

- Option 3: must be fully performed

- Fully performed contracts do not require Quantum Meruit, as these are complete and governed by the contract terms.

- Option 4: all of the above

- This option is incorrect because the statements are mutually exclusive.