A Person Inhales a Potentially Pathogenic Bacterium

A person inhales a potentially pathogenic bacterium. What defenses will the bacterium encounter as it travels through the human body?

A) hairs in the nasal cavity
B) mucus and cilia in the respiratory tract (if the bacterium enters the respiratory tract)
C) digestive enzymes in the stomach (if the bacterium enters the gastrointestinal tract)
D) phagocytes (if the bacterium enters the bloodstream)