Caffeine is a compound found in the seeds of many different plants, such as coffee beans, cola nuts, and cacao beans (the source of chocolate). The presence of this chemical in all three types of plants suggests that these plants A) inherited identical mutations B) share a common ancestry C) were exposed to the same type of radiation in the past D) were cloned from a caffeine plant

The correct answer is: B).

Explanation:

Caffeine is present in seeds of coffee beans, cola nuts and cacao beans.As all the three types of plants are capable of producing the same compound, that is, caffeine, this indicates that all of them have evolved from the same common ancestor.During evolution, a common ancestor must have undergone divergent evolution which might be due to several possible environmental factors like change in habitat.This divergent evolution caused by natural selection provided a competitive survival advantage for the individuals which develop mutations those make them distinctly different from the common ancestor and from each other (coffee beans, cola nuts and cacao beans).Eventually  reproductive barrier is established in between the variants and this results in speciation.