What Factor Below Does Not Account for the Relative Unimportance

What factor below does not account for the relative unimportance of farming in much of the New World prior to the arrival of Europeans?

A) An agricultural diet was not nutritionally superior.
B) Maize was difficult to harvest and process by hand.
C) Many groups continued to utilize hunting and gathering to supply sufficient protein.
D) The most productive domesticates were difficult to introduce to temperate areas.
E) New World cereal grasses required less space per plant, thus making a large extent of farming an unnecessary waste of time.