Most Natural Food Chains Are Only Four or Five Links

Most natural food chains are only four or five links long,rarely more.The number of trophic levels is limited because

A) there are more predators than herbivores.
B) the efficiency in utilizing the food eaten at each level is very low, about 10 percent.
C) winter kills off most insects and stops the food chains.
D) This is not correct; most food chains are much longer than four or five links.
E) nutrients cannot be passed after four or five levels.