Aggergate is usually found in:
Floodplains
Alluvial fans
Mines
For me I would have to go with C. They always have the same number and kinds of Chromosomes.
I would say 1 and 4 are the best answers. GMO crops are clones (genetically identical) so it reduces the genetic diversity making crops susceptible to new diseases.
A cow will eat grass in a field, the grass is the plant and the plant eater is the cow. (Srry if this is not what your looking for)