Select the most appropriate option to fill in the blanks.
The term 'germ' ______ an army of tiny terrors, including viruses, fungi, parasites and bacteria. These pathogens all have the ability to ______ from victim to victim, who is known as host. These look like microscopic monsters.

* For the first blank, the singular subject "The term 'germ'" requires a singular verb that means to include comprehensively. encompasses fits perfectly.
For the second blank, pathogens have the ability to travel or transmit from person to person, which is accurately expressed by the word spread.

Thus, option C provides the most suitable pair of words contextually and grammatically.