Experiments Using 'Potted Webs' Showed That the Number of Trophic

Experiments using 'potted webs' showed that the number of trophic levels in a food chain was limited by the

A) amount of energy at the bottom of the chain only if energy levels were kept far below natural levels.
B) amount of energy at the top of the chain in all cases.
C) amount of energy at the bottom of the chain in all cases.
D) size of the experimental pot.
E) amount of energy at the bottom is dependent on the number of relationships in which any species is involved.