Final answer:
The deductible mileage for Amy's commute to Garnet Corporation is 20 miles each way, totaling 40 miles round trip, which isn't listed among the provided answer choices, indicating a possible question error. The option (E) is correct.
Step-by-step explanation:
For Amy, an auditor assigned to work at Garnet Corporation for three months, the deductible mileage for each workday would be calculated by subtracting the normal commute from home to the office from the commute from home to Garnet. The normal home-to-office commute is 10 miles and the home-to-Garnet commute is 30 miles.
Therefore, the deductible mileage is the additional distance traveled beyond her usual commute to the office when traveling directly to Garnet from home, which is 30 miles minus 10 miles, resulting in 20 20-20-mile deductible each way. For a round trip, this would be 40 miles, so none of the provided answer choices (a. 0, b. 30, c. 35, d. 60, e. None of these) are correct, suggesting a possible error in the question or the need for an 'Other' option. Therefore, option (E) is correct.