Final answer:
Revenue from haircuts done in the last week of December should be counted in December, according to the accrual basis of accounting, which recognizes income when the service is performed.
Step-by-step explanation:
The question relates to the recognition of revenue for services provided which is a fundamental concept in accounting and business. It asks when the income from the haircuts should be counted. The answer is A. In December. This is because in accounting, the revenue is typically recognized when the service is performed, not when the money is received. This conforms to the accrual basis of accounting, where income is recorded in the financial statements for the period in which the service is performed, which in this case is December.