The figure below shows a phylogenetic tree.

Based on the above phylogenetic tree, what is the true order of difficulty to develop drugs to combat human pathogens that are prokaryotes, protists, animals, or fungi? (You do not need to consider the evolution of drug resistance by the pathogen.

• A. Animal pathogens, followed by choanoflagellate pathogens, fungal and nucleariid pathogens
• B. The fungal pathogen, followed by choanoflagellate pathogens, animal and nucleariid pathogens
• C. Nucleariid pathogen, followed by choanoflagellate pathogens, animal and fungal
• D. Nucleariid pathogen, followed by fungal, choanoflagellate, and animal pathogens

Answer: (A)