The authors of the paper "Action-Video-Game Alters the Spatial Resolution of Vision," (Psychological Science[2007]:88-94) concluded that spatial resolution, an important aspect of vision, is improved by playing action video games. They based this conclusion on an experiment in which 32 volunteers who had not played action video games were "equally and randomly divided between the experimental and control groups." Subjects in each group played a video game for 30 hours over a period of 6 weeks. Those in the experimental group played Unreal Tournament 2004, an action video game. Those in the control group played Tetris, a game that does not require the user to process multiple objects at once.
Based on this description of the experiment, which control is part of the experiment design? Check all that apply.

A. a control group
B. random assignment
C. direct control
D. blinding

The correct answer is letter A; D

The control group is the group that will not be tested, it will be in normal situations, outside of what is being tested, for example, in testing a drug, the control group will not use the drug.

Blinding, those involved do not know in which group, control and experimental the intervention was carried out. Survey details remain anonymous.

The experimental group is the group that will be tested in some way, in the example above, the experimental group would take a certain drug, and then the reactions and differences between the control group and the group that used the drug would be compared.

in 342 bc j._c. egypt fell into the hands of the persians, under the reign of nectanebo ii

greek city-states unite in a revolt against the persian empire at the beginning of the fifth century bc. j.-c  

from the year 660 or 659 bc ad, cyrus preached the revolt against the medes to deliver the persians.