Resin is a plant secretion that hardens when exposed to air; fossilized resin is called amber. Although Pliny in the first century recognized that amber was produced from “marrow discharged bytrees,” amber has been widely misunderstood to be a semiprecious gem and has even been described in mineralogy textbooks. Confusion also persists surrounding the term “resin,” which was defined before rigorous chemical analyses were available. Resin is often confused with gum, a substance produced in plants in response to bacterial infections, and with sap, an aqueous solution transported through certain plant tissues. Resin differs from both gum and sap in that scientists have not determined a physiological function for resin.
In the 1950s, entomologists posited that resin may function to repel or attract insects. Fraenkel conjectured that plants initially produced resin in nonspecific chemical responses to insect attack and that, over time, plants evolved that produced resin with specific repellent effects. But some insect species, he noted, might overcome the repellent effects, actually becoming attracted to the resin. This might induce the insects to feed on those plants or aid them in securing a breeding site.Later researchers suggested that resin mediates the complex interdependence, or“coevolution,” of plants and insects over time. Such ideas led to the development of the specialized discipline of chemical ecology, which is concerned with the role of plant chemicals in interactions with other organisms and with the evolution and ecology of plant antiherbivore chemistry (plants' chemical defenses against attack by herbivores such as insects).
Of the following topics, which would be most likely to be studied within the discipline of chemical ecology as it is described in the passage?
Seeds that become attached to certain insects, which in turn carry away the seeds and aid in the reproductive cycle of the plant species in question
An insect species that feeds on weeds detrimental to crop health and yield, and how these insects might aid in agricultural production
The effects of deforestation on the lifecycles of subtropical carnivorous plants and the insect species on which the plants feed
The growth patterns of a particular species of plant that has proved remarkably resistant to herbicides
Insects that develop a tolerance for feeding on a plant that had previously been toxic to them, and the resultant changes within that plant species
原文：discipline of chemical ecology是研究植物化学物质和其他有机体&PAC的相互作用。