If Horizontal Gene Transfer Was Predominant in Early Evolution, How

Multiple Choice

If horizontal gene transfer was predominant in early evolution, how would this affect our ability to reconstruct the tree of life?

A) Horizontal gene transfer blurs the concept of species, making it difficult to delineate ancestral species.
B) Horizontal gene transfer resulted in chloroplasts that confuse the plant lineage.
C) Horizontal gene transfer places viruses firmly at the beginning of the tree of life.
D) Horizontal gene transfer means that life-forms do not share a history of common descent.