The correct answer is "When an indivisible contract for a lumpsum is partly performed." Quantum Meruit:The phrase "as much as is earned" is literally translated as "quantum meruit."When one party to a contract is prevented from completing his contract performance by the other party, he can sue for quantum meruit.As a result, he must be compensated fairly for the portion of the contract that he has already completed.Important Points Quantum Meruit is, payment in proportion to the amount of work done, where one of his parties has fulfilled part of his promise and then the contract person is breached, then a claim for quantum merit arises.When the original contract is discharged, i.e. when the indivisible contract for a lump sum amount of a debt is partly executed, then the claim of quantum merit cannot be successful.