Which theorist(s) used operant conditioning to explain why an infant becomes attached to the caregiver, who is a source of reward, through positive reinforcement? A. Schaffer
B. Dollard & Millard
C. Wartner
D. Harlow

Ronald sees that his employer's stock has grown from $20 a share to $60 a share this year, while most stocks have seen only 5% growth. his employer offers to let him convert a large portion of his salary into stock options. what is not a valid reason to turn down the stock offer? a)stocks with high returns have high volatility, and ronald's company may not grow further. b)ronald may be taxed more for capital gains than he would be for employment income. c)stock options are illiquid, and ronald may not be able to use them to pay for unexpected bills. d)ronald would be committing stock fraud if he exercises the options.