Question

multiple choice question the arrow points to an ancestral cell type often referred to as the last common ancestor the kingdom of viruses eukaryotes proto - prokaryotes

Explanation:

The last common ancestor (LCA) is the most recent ancestral cell type from which all organisms in a particular group are descended. Viruses are not part of the three - domain system shown (Bacteria, Archaea, Eukarya). Eukaryotes are a domain and not the ancestral cell type. Proto - prokaryotes is not the correct term for this ancestral cell. The LCA is the correct ancestral cell type referred to by the arrow in the context of the tree of life.

Answer:

the Last Common Ancestor