Who is the first individual in the combat health support chain to make medically substantiated decisions based on military occupational specialty-specific medical training?
Correct Answer: B
Rationale: The correct answer is 'Physician assistant.' Physician assistants are trained to make medically substantiated decisions based on their specific medical training within the combat health support chain. Choice A, 'Physician,' is incorrect as they may be involved but are not typically the first in line for such decisions as physician assistants. Choice C, 'Combat medic,' is incorrect as they usually provide immediate medical care but may not be the first to make medically substantiated decisions. Choice D, 'Combat lifesaver,' is incorrect as they are trained to provide basic life-saving interventions but may not have the specialized medical training to make complex medical decisions.