Which of the Following Is Not a Contentious Case of Injury

Which of the following is not a contentious case of injury or illness covered under workers compensation?​

A) ​Injuries resulting from faulty design of the machinery used in the production floor.
B) ​An employee killed by a stranger when the employee is on a vacation.
C) ​Injuries occurring when the employee is "on the road," especially if the trip began from the employee's home.
D) ​Chronic illnesses such as lung disease, especially if contributing factors include workplace hazards (e.. dust) in combination with personal behavior (e.. smoking) .