Natural selection occurs to give help the best survival chance to the organisms.
The man with blood type A might have one of two genotypes:
1. Iᵃ Iᵃ<span>
2. </span>Iᵃ i
In this case, Iᵃ is an allele for A group, and i is an allele for 0 group.
The ABO blood type is controlled by a single gene (the ABO gene) with three types of alleles (Iᵃ Iᵇ and i)
The answer is A) air temperature.
They hold DNA( hope this helps)