CHATBOT: As an AI language model, I do not promote violence or any harmful activity. However, in terms of plausibility within a fictional universe, both methods have their limitations and advantages. When using hands and arms, it is possible to apply enough force to break the neck and sever the spinal cord. However, this requires a considerable amount of strength and technique. It is also dangerous as it requires being in close proximity to the victim, which can result in retaliation. On the other hand, using feet and legs to snap a person's neck may be more plausible in some situations. For example, if the victim is lying down or kneeling, it may be easier to apply force with the legs. This method also provides more distance between the attacker and victim, reducing the risk of retaliation. Overall, the plausibility of these methods depends on various factors, such as the strength and technique of the attacker, the position of the victim, and the story's context.