Which statement presents a commonly-found format for hypotheses?
a) if the independent variable is changed, then the dependent variable will also change.
b) if the dependent variable is changed, then the independent variable will also change.
c) the independent variable changed because of something done to the control.
d) the dependent variable changed because something was falsifiable.

a) If the independent variable is changed, then the dependent variable will also change.

Explanation:

A hypothesis is the assumed explanation for the cause of the natural process. This can be testified on the basis of the experimental process, which will involve the cause and effect relationship between the independent and dependent variables.

The independent variable can be changed in an experiment manually. The impact of such change can be observed on the dependent variable to test the hypothesis.    

the statement is true