Which of the following variables would be the easiest to control? political opinion a teenager's diet atmospheric air pressure amount of antibiotic added to a bacterial culture

Amount of antibiotic added to a bacterial culture would be the easiest to control

Explanation:

The thing that has a tendency to change or vary during the period of an experiment is defined as a Variable. When number of variables in an experiment increases the process of controlling will be very tedious. Consider the first option political opinion.

Here there will be many number of variables such as like, dislike, better, etc. When we consider the teenager's diet it will also be not limited in number. When the amount of antibiotic added to a bacterial culture is considered the number of variable in this experiment will be only one. Hence, it will be easier to control.