Answer:
c. the causation in fact, but not the proximate cause, of Ethel’s death.
Explanation:
The law includes two forms of causation: cause-in-fact, and cause-in-proximity (or legal).
The "but for" check decides the cause-in-fact: However the outcome would not have happened without the action.
Both requirements should be met for such an action to be considered to cause harm; proximate cause is a legal restriction on cause-in-fact.