Imagine Two Different Species of Caterpillar Are Feeding on a N

Imagine two different species of caterpillar are feeding on a N. attenuata plant. One of these species is M. sexta. How can this plant differentiate between M. sexta (which are unaffected by the plant's usual chemical defenses) and the other caterpillar species?

A) M) sexta caterpillars are much heavier than the caterpillars of other species. N. attenuata plants can "sense" the weight of this caterpillar, triggering the production of volatile chemical signals.
B) M) sexta caterpillars have fewer legs compared to caterpillars of other species. N. attenuata plants can "sense" the number of legs on different caterpillars, triggering the production of volatile chemical signals.
C) M) sexta caterpillars secrete nicotine (which is present in the leaves of N. attenuata plants) . These plants can "sense" excess nicotine on their leaf surfaces, triggering the production of volatile chemical signals.
D) The saliva of M. sexta caterpillars has a distinct chemical composition. N. attenuata plants recognize certain chemical compounds in this saliva, triggering the production of volatile chemical signals.
E) N) attenuata plants cannot differentiate between caterpillars of different species. Volatile chemical signals are produced in response to predation by any caterpillar.