A Petroff- Hauser Counting Chamber Is A(n)

A Petroff- Hauser counting chamber is a(n)

A) device that counts cells as they interrupt an electrical current.
B) glass slide containing an etched grid for counting microbes directly using a microscope.
C) apparatus that traps bacterial cells on a membrane filter where they can be counted.
D) device that measures the amount of light that passes through a culture.
E) device used to count numbers of bacterial colonies on a Petri plate.