A bacteriophage can infect ________.

a. the lungs

b. viruses

c. prions

d. bacteria

Acellular creatures are viruses. They're obligate intracellular parasites that don't live outside but do live inside a host. They don't have their own enzymatic machinery and instead rely on the machinery of the host cell to replicate.

Adenovirus, HPV (human papillomavirus), HIV (human immunodeficiency virus), and a variety of other viruses are examples.

Bacteriophages are viruses that infect bacteria rather than viruses themselves.

Bacteria have no lungs.

Prions are proteinaceous infectious particles that are smaller than viruses and have a proteinaceous origin. They don't have any genetic material in them. Prions cannot be infected by bacteriophage.

Viruses can infect plants, animals or microorganism including archaea and bacteria.

However, bacteriophages are the viruses that have the capability to infect bacteria. For example, T4 is a bacteriophage that can infect a bacterium Escherichia coli.