Why was Daniel Hernandez regarded as a hero?

A、During the horrible shooting, he courageously ran through the danger to save his boss and friend—Gabrielle Giffords.;

B、Daniel held Gabrielle Giffords’ head up so she could breathe.;

C、Daniel spoke tender words of sympathy and told Gabrielle Giffords everything would be fine. ;

D、Daniel stayed beside Gabrielle Giffords in the ambulance all the way to hospital.