attacks may involve individuals posing as new employees or as current employees desperately requesting assistance to avoid getting fired.

Explanation:

I Believe there is more to this Question however I will answer it the best I can. I believe it is Social Engineering.

Social Engineering definition:: the use of centralized planning in an attempt to manage social change and regulate the future development and behavior of a society

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answer; i believe the correct answer is (4) flip a coin as each participant arrives,heads indicates assignment to the first group: tails indicates assignment to the second group;