Warren worked in an office. He had no criminal record, had never had a complaint made against him about his work or his conduct, and had been a...

Warren worked in an office. He had no criminal record, had never had a complaint made against him about his work or his conduct, and had been a faithful employee for nearly 20 years. One day, Warren followed his supervisor to his home and fatally shot him. The estate of the supervisor sued the company, claiming it should have been aware of Warren's growing frustration with work. The company's best defense will be that

a) 

there was no way to reasonably foresee that the incident would happen.

b) 

the incident occurred away from the office.

c) 

the killing was the result of a personal conflict between Warren and the supervisor.

d) 

even if the company had been aware of Warren's difficulty with his supervisor, Warren did not have any criminal history.