What meaning of "Shock" is being used in this sentence?

"The shock was so terrifying, I had to go to the hospital."

A) an unpleasant or disappointing surprise

B) a mechanical damper; absorbs energy of sudden impulses

C) an instance of agitation of the earth's crust

D) a pile of sheaves of grain set on end in a field to dry; stalks of Indian corn set up in a field​