Which Statement Accurately Describes a Way Plants Allocate Carbon That

Which statement accurately describes a way plants allocate carbon that is not used in respiration?

A) Plants allocate carbon as a defense against herbivory.
B) Plants allocate almost all carbon to increasing photosynthetic tissue.
C) Plants growing in areas with high plant density allocate a higher proportion of NPP to roots relative to leaves and stems.
D) Plants growing in deserts allocate a lower proportion of NPP to roots relative to leaves and stems.