Choose the best thesis statement for an analytical essay. a.approximately 12,000 u. s. helicopters were used in the vietnam war. b.a man named charles kelly commanded the first helicopter rescue unit in the vietnam war. c.the roots of aeromedical evacuation, also known as "life flight" helicopter rescue, can be traced back to the vietnam war. d.therefore, if your life is saved by a rescue helicopter, you can know that it is in part due to the vietnam war "dustoff" crews.