The correct answer is option B) "Species trees should be constructed using multiple loci (both nuclear and mtDNA)".
Explanation:
Gene genealogy is defined as the inference of relationships between individuals by using DNA testing in combination with the analysis of traditional genealogical and historical records. Gene genealogies could not be established using an unique genetic loci, since not always the same loci vary among individuals. Therefore, species trees should be constructed using multiple loci (both nuclear and mtDNA), to avoid erroneous inferences obtained by analyzing loci that do not vary among individuals.
2 would be A because fertilization is where the sperm cell and egg unite. 3 would be C because in the picture you can see how the division is occuring.
