Answer: D

Explanation: The correct answer is D, “Service.” A contract of service refers to the relationship between an employer and an employee, where the employee works under the control and supervision of the employer, often described as the “master-servant” relationship.

Rundown: The selected answer “D” was chosen because a contract of service involves an employment relationship where the worker is subordinate to the employer and is subject to their control, which is a key characteristic of such contracts.