Answer:
The correct answer is the option C: a vertical analysis using sales as the base.
Step-by-step explanation:
To begin with, the concept known as ''vertical analysis'' is a tool or method used in the financial statements whose main purpose is to analize the changes that were made in the financial statement being analized and it uses a base figure within the statement in order to list each item inside the paper as a percentage of the base used.
To sum up, in this case, Luke has most likely provided a vertical analysis using sales as the base in order to determinate the percentage of the other items according to the sales.