the average temperature of the water samples the brand of microscope slide used the magnifying power of the microscope the proper identification of each microorganism
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: Students want to compare the size of microorganism communities in 500-milliliter water samples from each of two ponds. Which factor most likely will affect the accuracy of their observations?
Possibilities:
- the average temperature of the water samples
- the brand of microscope slide used
- the magnifying power of the microscope
- the proper identification of each microorganism

the magnifying power of the microscope