1. Suppose you are interested in finding the causal effect of weekly injections of 800mg of testosterone cypionate in Chads bench press. Chad takes the steroids for 16 weeks. Which of the following is the best counterfactual?

Group of answer choices

a. Chads bench press increase after 16 weeks had he NOT taken the testosterone.

b. Chads bench press increase over 16 weeks exactly one calendar year ago.

c. Brads bench press increase over the same 16 weeks as Chads workout partner, except Brad doesnt use testosterone.

d. What Chad thinks would have been the increase in his bench press over the 16 weeks had he not used testosterone.

e. All of the above counterfactuals are pretty bad.

2. True or False: Almost all regression models suffer from omitted variables bias.

Group of answer choices

True

False

More information is needed