maybe A&C? not entirely sure, but thats my best guess!
Answer- you would use a Punnet Square to cross the kinds. In order to know which ones to use, you'd have to test them all. Without knowing what each letter codes for it is hard to show
Because there will be no bias if the reasearcher knows which drug is being given and the subject wont know what they are being given so both may assume that the subject is going to feel happier and expect to have an elevated mood and relieve feelings of depression. Hope this helps :)
Humans adapt after prolonged exposure to a constant stimulus because we detect the potentially important changes. It is also because we tend to be curious about the things that are happening around us which we try to adapt and adjust.