Which Statement About Net Secondary Production Is True

Which statement about net secondary production is true?

A) In most ecosystems, net secondary production is only a small fraction of NPP.
B) As a percentage of NPP, net secondary production is usually higher in terrestrial than in aquatic ecosystems.
C) In most ecosystems, most of the net secondary production is associated with herbivores.
D) Net secondary production is the balance among ingestion, egestion, and activity level.