_______________ are the brain's communication specialists, transmitting information to, from, and within the central nervous system

Your clock makes a clicking sound just before the alarm. Initially that sound didn't waken you, but now it does, due to classical conditioning. What is the unconditioned stimulus?

a. The clicking sound b. The alarm c. Waking up d. The clock

Research with sadomasochists found that about 40% ____

a. reported that "straight" sex is more satisfying than sadomasochistic activities b. played either a dominant or a submissive role but not both c. engaged in behaviors that caused only minor pain d. reported that they seek to injure others or be injured themselves