Answer:
B) You measure the quantity of the appropriate pre-mRNA in various cell types and find they are all the same.
Step-by-step explanation:
In the above scenario, we are using the control gene and we should know about the control gene is that its expression is either at transcription level or at translation level. For this situation we should examine the pre-mRNA stage of control gene in various cells because it is control gene so it should be present in various cells.
So, the best practice is to quantify the pre-mRNA level of gene then we can effectively solve the experimental problem and find the gene expression either it is at transcription or translation level.