Living factors in an environment like bacteria, plants and animals are:

the relative standard reduction potential of the half-cell in which reduction occurs; more positive than the other half-cell. reduction is a chemical process in which electrons are added to an atom or an ion; it always occurs accompanied by oxidation of the reducing agent.

option c is the correct answer.

on island x the species needed to adapt because they were being subject to predators which didn't inhabit island y.