The correct answer is D) Helmsman. The helmsman is responsible for lowering the survival craft in the event of an emergency. This is because the helmsman is in control of the vessel's steering and maneuvering, which is crucial for the safe and controlled lowering of the survival craft. The helmsman's position and training make them the most qualified to oversee this critical task during an abandon ship situation. The other options are incorrect because the roustabout is a general crew member, the first and last men aboard have other specific duties, and the helmsman is the one responsible for the lowering of the survival craft according to maritime regulations and standard operating procedures.