Question

what role did the resting rate play in the bromothymol blue experiment?
a hypothesis
a null hypothesis
a control
a dependent variable

Explanation:

In an experiment, the resting rate can serve as a baseline for comparison. A control is a standard against which experimental results are compared. The resting rate in the bromothymol blue experiment likely provided a reference point to measure changes, making it a control. It is not a hypothesis (a proposed explanation), a null hypothesis (a statement of no - effect), or a dependent variable (the variable being measured as a result of changes).

Answer:

C. a control