Which of the following firms is determining its progress toward completion of a performance obligation on a cost-to-cost basis? O A firm estimates the total costs associated with fully completing the obligation, and then divides them by the total number of work hours spent on the obligation to this point. O A firm calculates the costs it has incurred thus far in relation to the obligation, and then divides these costs by the total number of work hours spent on the obligation to this point. O A firm calculates the costs it has incurred thus far in relation to the obligation, and then compares them to its estimated costs for completing the obligation to this point. O A firm calculates the costs it has incurred thus far in relation to the obligation, and then compares them to the estimated total costs associated with fully completing the obligation