Let's say your name is Gilligan, you've survived a shipwreck and you're stranded on a desert island. You happen to have been stranded with a medical doctor that has a limited stock of medical supplies. One of your shipmates is in desperate need of a blood transfusion but doesn't know his blood type. You do know your blood type. How could you type his blood with your knowledge and limited medical supplies?

•there must be variation for the particular trait within a population.

•the variation must be inheritable (that is, it must be capable of being passed on from the parents to their offspring).

•individuals with one version of the trait must produce more offspring than those with a different version of the trait.good

explanation:

that is wrong, its not thymus.

multiple allele inheritance is traits controlled by more than 2 alleles (ex: pigeons having 3 alleles of one gene govern their feather color).   so the answer is a.