Any practices should best be based on a research - this is the correct answer. (a. child development and research) Research is the best source of actual knowledge, rather than people's best guesses (people's best guesses might lead government regulations, but it would be better if they also followed research results.).
Possibly more trades could take place around the world
The answer to the first unknown in the problem is the "EGO" while in the second unknown in the problem is referring to "face-to-face discussions with". In modern psychoanalyst differ from the traditional Freudian psychoanalysis in such a way that they focus on the EGO as a motivating force of behavior and they favor face-to-face discussions with their patients.