Final answer:
A counterexample can be constructed to prove that the argument is invalid. It is possible for Jenny to not be killed in an automobile accident and still be dead due to other factors.
Step-by-step explanation:
In this logical argument, we have a conditional statement: If Jenny was killed in an automobile accident, then Jenny is dead. The argument then states that Jenny was not killed in an automobile accident. Based on these premises, the conclusion is drawn that Jenny is not dead. To establish whether this argument is valid, we can construct a counterexample.
A counterexample is an instance that satisfies all the premises of an argument but demonstrates that the conclusion is false. In this case, a counterexample would involve a situation where Jenny was not killed in an automobile accident but is still dead. For example, let's say Jenny died of a natural cause or an illness, not related to any car accident.
By showing this counterexample, we can conclude that the argument is invalid. It is possible for Jenny to not be killed in an automobile accident and still be dead due to other factors.