Which of these is a similarity between early indus river valley and early chinese (shang) civilizations?

Agriculture was a significant part of the economy. Both of these civilizations were created near a river which makes the lands around it encompasses a lot of good nutrients for the plants. This makes it easier for both these civilizations to preserve a good amount of crops as their main technique of obtaining wealth.

c is the answer for this

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;