The answer is the second choice: variation, overpopulation, adaptation
Answer:
The correct answer would be "Each parent is either M or MN".
Co-dominance is the condition in which both the alleles express themselves completely when present in the heterozygous condition.
The blood group of the offspring can be of M type in two conditions:
1. When both the parents are of M blood group
2. When both the parents are heterozygous for the blood group that is, they both are MN.
Your body can over work yourself and than give out
All you would have to do is sum them up cause their going the same direction.