Alexis uses cocaine, which activates her sympathetic nervous system. Expecting her dealer, her hands shake and her heart pounds when she hears a knock on the door. Which alternation below CORRECTLY identifies the neutral stimulus, the CS, and the UCS?A. Neutral stimulus ---- knock on the door; CS---cocaine; UCS----cocaineB. Neutral stimulus ---- knock on the door; CS---knock on the door; UCS ---- pounding heartC. Neutral stimulus ---- knock on the door; CS--- Knock on the door; UCS cocaineD. Neutral stimulus ---- cocaine; CS--- Knock on the door; UCS cocaine