An experiment was designed to measure the effect of sulfur dioxide emissions from a power plant on the ph of rain falling downwind of the plant. in this experiment, the average ph of rainwater upwind from the plant would be considered the

control

Explanation:

According to my research on experimental design terminology, I can say that based on the information provided within the question this factor is known as the control factor. This is the factor within an experimental design that the researcher has complete control over during the experiment. Unlike variables that he/she does not control.

I hope this answered your question. If you have any more questions feel free to ask away at .