The age of viability occurs at some Answers: a19 and 21 b: 25 and 30 c. 26 and 32 d. none of the above. Question 38: During the first stage of labor Answers: a. mom begins intense pushing b. the head appears c. the cervix dilates d. none of the above. Question 39: Which of the following does not belong with the others Answers: a. case study b. survey c. experimentation d. naturalistic observation. Question 40: Example of an Answers: a. unconditioned stimulus b. positive reinforcer c. conditioned stimulus d. none. Question 41: If a woman has three daughters and is pregnant with her fourth child, there is a 75% chance the child will be a girl. Answers: True False.