Answer: C. the base period amount.
Explanation: While implementing a horizontal analysis on a given income statement, we compute a percentage change in any individual item by dividing the dollar amount of change from base to current time period with the base period amount.
i.e. % Change in Individual item = [tex]\frac{Current\ Dollar\ - Base\ Dollar }{Base \ period \ amount}[/tex]
Therefore, the correct option in this case is (c)