C. Agar provides a solid surface for bacterial growth.
Agar is a substance obtained from red algae which when added to a culture media, provides a solid surface for the growth of bacteria. When the agar is not added then the culture media remains as the broth and when the agar is added then the broth gets solidified.
Agar is added 1.5-2% in the broth to get solidified. The growth of the bacteria depends on the amount of agar added. Agar is used for the growth of bacteria because it has gel like properties which holds the nutrients evenly and the bacteria can use it accordingly.
This might help:
https://quizlet.com/1965478/environmental-health-test-1-flash-cards/
The answer is C the moon is between the earth and sun
