Final answer:
The correct answer is D. The skin is not penetrated in the case of a closed chest injury. The skin remains intact, which differs from open injuries where the skin can be breached, leading to potential infections.
Step-by-step explanation:
The correct answer to the question regarding the skin's status in the case of a closed chest injury is D. The skin is not penetrated. A closed chest injury implies that although there might be damage to the internal structures, such as contusions and lacerations, the outer layer of skin remains intact. Thus, the skin has not been penetrated or compromised in such an injury.
In contrast, statements A and B are incorrect because internal damages, such as internal contusions and lacerations, can indeed occur even when the skin is not breached. The statement C is also not accurate in this context as it describes an open injury where the bone pierces the skin, which is not the case with a closed injury.
The skin acts as a barrier and its integrity is crucial to prevent pathogens from entering the body and causing infection. When the skin barrier is damaged as suggested in statements B and C (which is not applicable in the case of closed injuries), it can lead to various complications, including microbial invasion and wound infections.