Economic                 Geographic               Social
                   Aspect                      Aspect                      Aspect

C)                     3                                1                               2
 

1. the farms were rectangular in shape and perpendicular to the river;
     Correct !

 2. the people put their efforts into developing agriculture;
     Not Correct !   (Agriculture is not a social activity) Economic ?

3. the corvées (free labour) promoted the exchange of services.
    Not Correct !   (Exchange of services is not economic) Social ?