The correct answer is: A. randomize it
If you can’t fix the variable, you should randomize it. This means that you should assign the variable to different values in a random way. This will help to ensure that the results of your study are not biased.
Option B, non stratify it, is incorrect. Stratifying a variable means dividing it into different groups. This is not necessary if you can’t fix the variable.
Option C, generalize it, is incorrect. Generalizing a variable means making it more general. This is not necessary if you can’t fix the variable.
Option D, none of the mentioned, is incorrect. Randomizing the variable is the best way to deal with a variable that you can’t fix.