Which of the Following Statements Are True of Vectors and the Diseases

Which of the following statements are true of vectors and the diseases they spread? (Read carefully and select all of the correct statements.)

A) The human body louse is the vector of typhoid fever.
B) Mosquitoes are vectors of malaria and yellow fever.
C) Vectors spread disease when they bite humans or other warm-blooded animals.
D) The deer tick is the vector of Lyme disease and West Nile encephalitis.
E) Fleas are vectors of bubonic plague, epidemic typhus, and sleeping sickness.
F) The vector of a pathogen may be an essential part of the life cycle of that pathogen.