The Presence of High Levels of Carbon Monoxide in the Blood

The presence of high levels of carbon monoxide in the blood of a victim found at the scene of a suspicious fire is proof that the victim:

A) was the arsonist.
B) perished after the fire started.
C) died before the fire started.
D) died elsewhere and was brought to the fire scene after death.
E) was not a cigarette smoker.