Which of the following is used in a randomized groups design?

Mary's grandmother, Pearl, is from the Old Country. Although she knows some English, she continues to speak her native tongue. Pearl can't go anywhere without a member of the family because she can't communicate with people about prices, directions, bus routes, etc. Pearl's resistance to learning English is most likely the result of ______

a. a lack of intelligence b. age. Studies show that after the age of 60 learning a second language is nearly impossible. c. the length of time she has spent speaking her native language d. the benefits she receives for not speaking English

A baby is considered to be in critical condition if her score on the Apgar scale is below

A) 6. B) 5. C) 4. D) 3.