The Presence of Herbivorous Insects on Plant Populations Is Thought

The presence of herbivorous insects on plant populations is thought to contribute to the diversity of both plants and insects through both ecological and evolutionary processes. Which of the following statements describes a scenario in which plant diversity increases due to an evolutionary process involving natural selection by herbivorous insects?

A) Plant diversity increases because when one individual survives after the rest of its population is eaten, there is more space for other species to grow.
B) Plant diversity increases because farmers plant crop plants with and without the Bt genes in their fields.
C) Plant diversity increases after the appearance of a pesticide-resistant insect species in a sympatric speciation event.
D) Plant diversity increases due to a sympatric speciation event involving a mutation, conferring greater toxicity to an alkaloid that has arisen and spread through an insect subpopulation.