Answer:
Option a (manipulated variable) would be the appropriate choice.
Explanation:
- To analyze the influence on something like a dependent variable, another modified variable seems to be an important variable responsive to modifications in quite an analysis.
- Plainly defined, the variable has been adjusted to determine its effect on the overall outcome of the study. There would be only one manipulated component in a correctly planned analysis.
The other options offered are not relevant to the situation described. So, the solution above is the best one.
