In the short run, which of the following BEST describes the relationship between a variable factor (like labor) and the total output produced? a. There is a directly proportional relationship, meaning as you increase the variable factor, the total output increases at a constant rate. b. The total output initially increases at an increasing rate as you add more of the variable factor, but eventually this rate of increase will slow down. c. The total output will eventually decrease as you increase the variable factor, even if the fixed factors remain constant. d. The total output remains constant regardless of how much of the variable factor is used