Given below is an imaginary pyramid of numbers. What could be one...

The given figure shows spindle shaped pyramid of number in single tree ecosystem. Here a single large sized tree provides food to a large number of herbivores which support a few carnivores and the later are eaten by small number of top carnivores. So, here PP is used for producer, i.e., single tree, $P C$ is Primary Consumers, i.e., large number of insects, SC is secondary consumers, i.e., small insectivorous birds and TC is Top consumers which may be eagles or falcon, etc.