Selective breeding is the process of breeding plants or animals so that they inherit particular traits from their parents. which of these is not possible with selectively breeding a crop species? a. the crop becomes more tolerant to droughts b. the quality and yield of the crop improves c. the crop becomes resistant to bacteria and fungi d. the offspring will have different traits from the parents

Selective breeding is also known as "artificial selection", which essentially means "made by humans", thereby, what is possible is up to human imagination, endeavor and how much research and disposition is assembled in order to achieve a particular breeding goal.  

So, nowadays that the study of the genomes is advanced, its a matter of how much time, energy and resources are combined to lay out an assignment that sorts an specific set of instructions needed to create a particularly desired organism (or trait, in this case). Accordingly, any of those traits mentioned above could be achievable by modern selective breeding.

D. the offspring will have different traits from the parents

Selective breeding or artificial breeding is a process that involves the breeding between two selected parents (plants or animals) exhibiting desired features useful for human population. The offspring produce obtains the useful traits of both parents. The relevant outcomes of selective breeding may include drought tolerant, improved quality and bacteria and fungi resistant crops.

On the basis of the above description, D. the offspring will have different traits from the parent is not possible with the selective breeding a crop species. As, the offspring exhibit traits of both of the parents.

any abiotic or biotic factor in an ecosystem that causes a population's size to slow or decrease is a limiting factor.