The percentage-of -completion method of accounting for long-term construction-type contracts is preferable when a.

The percentage-of -completion method of accounting for long-term construction-type contracts is preferable whena. Estimates of costs to complete and extent of progress toward completion are reasonably dependable.b. The collectibility of progress billings from the customer is reasonably assured.c. A contractor is involved in numerous projects.d. The contracts are of a relatively short duration.