The argument assumes the incidents are caused mainly by drone design, not by other correctable factors.
A This minimizes how serious the incidents were, but it does not challenge the claim that accidents will become more common.
B This compares drones to other delivery methods, but the argument is not about which method is safer overall.
C Even if no new drones are added, increased usage could still lead to more incidents.
D This suggests the problem is persistent over time, which actually supports the idea that accidents will continue as usage grows.
E This shows that the incidents may have been caused by poor human oversight, not by flaws in drone design. If better training is provided, accident rates could fall even without new safeguards. Correct answer.
The answer is E