In an Experiment Investigating the Effects of Alcohol Consumption on the Ability

In an experiment investigating the effects of alcohol consumption on the ability to operate a punch press machine

A) alcohol consumption is the independent variable and ability to operate the machine is the dependent variable. \
B) ability to operate the machine is the independent variable and alcohol consumption is the dependent variable.
C) the experimental group is tested on ability to operate the machine and the control group is not.
D) the control group operates the machine under the influence of alcohol and again after the effects, if any, have worn off.