I THINK C.) anaerobic bacteria
The only consumables that is not digested and is immediately absorbed, would be water, it is nothing but a polar compound that does not yield as much energy as all of the other molecules.
The answer is B, multiple alleles.
Codominant is when the gene pair in a heterozygous are both fully expressed.
Incomplete dominance is when one allele is not fully expressed over its paired allele.