A company's normal operating activity is to produce 500 units per month. During its first two months of operaetion, it produced 100 units per month. Following a great article about the product, product spiked to 1,000 units per month, but the spike only lasted for one month. Which of the following best approximates the company's relevant range?
a. 450-510 units.
b. 100-1,000 units.
c. 500-1,000 units.
d. 100, 500, or 1,000 units.