Final answer:
The contract between James and Kenneth is voidable by Kenneth due to the physical duress exerted by James through the threat of violence. Economic duress is not the accurate classification here as the duress involved is physical.
Step-by-step explanation:
In the scenario described, physical duress has been exerted on Kenneth by James, making the contract voidable at Kenneth's option. The use of a direct threat to coerce someone into signing a contract nullifies the concept of free consent, a foundational element of a valid and enforceable contract.
Furthermore, while the term economic duress typically refers to situations where financial pressure is applied, it does not directly apply in this case as the duress involved here is physical in nature. However, the threat implies economic repercussions, which muddies the classification slightly. Nonetheless, the primary issue is the physical coercion used, which makes the contract voidable by the threatened party.
a. This contract is voidable at Kenneth's option; and b. James has committed physical duress against Kenneth. Economic duress does not precisely describe the situation since the threat was of physical harm, not economic harm, despite the contract involving a payment.