What part of the client's body should the cape not touch?

The correct answer is that the cape should not touch the skin. In the context of hair services, it is important to prevent the cape from coming into direct contact with the client's skin to maintain hygiene and comfort. A cape that touches the skin can lead to irritation or discomfort due to hair, chemicals, or products used during the service. Additionally, keeping the cape away from the skin reduces the risk of cross-contamination from hair products or color that could potentially cause allergic reactions or skin issues.

The other options, while they may relate to common concerns during a service, do not address the primary issue of hygiene and skin irritation. The neck, head, and shoulders are natural points of contact during the draping process, and these areas can generally be covered by the cape as long as proper hygiene practices are followed.