Vertebrates have a back bone. They have living endoskeleton, pharnyx and efficient respiration, advanced nervous system, and paried limbs.
Answer:
B) Natural selection favored rabbits that were resistant to the virus
Explanation:
Most likely, virus resistance occurred over time, as a consequence of mutation. Individuals that carried the resistance mutation become favourable by natural selection.
Natural selection is evolutionary mechanism which favours traits of an organism that help him survive and reproduce (increase organism's fitness). In the example above, resistant rabbits that survived had the favorable trait (resistance) by natural selection.
3% of earth's water is actually fresh, not salty ocean water
