Final answer:
Archie should sue for the remedy of reformation in order to have the written agreement modified to reflect the original intent of 50 days for delivery, correcting the mutual mistake without cancelling the contract.
Step-by-step explanation:
In the scenario described, if Rich and Archie have a dispute over the delivery date of the champagne and Archie still wants to deliver the champagne, then Archie should sue for the remedy of reformation.
AReformation is a legal remedy that corrects a written agreement to conform to the original intent of the parties when there was a mutual mistake, as is the case with the incorrect delivery date of 5 days instead of the intended 50 days. Unlike rescission, which would terminate the contract, or restitution, which would require returning any benefits received, reformation modifies the contract to reflect what the parties actually agreed upon.
The other options provided, such as rescission, restitution, and reliance, do not fit the scenario because they involve either cancellation of the contract, returning received benefits, or compensation for loss incurred due to reliance on the contract. Since the intent is to fulfill the contract with the corrected terms, reformation is the appropriate legal action for Archie.