Choice "d" is correct. While the cash basis of accounting is used by most taxpayers for tax purposes, the accrual basis method of accounting for tax purposes is required for the following:

1. The accounting for purchases and sales of inventory,

2. Tax shelters,

3. Certain farming corporations, and

4. C corporations, trusts with unrelated trade or business income, and partnerships having a C corporation as a partner provided the business has greater than $5 million average annual gross receipts for the three-year period ending with the tax year.

The information in the facts tells us that Dart does not maintain inventory, so the first item that requires accrual method of accounting does not apply. However, the facts also tell us that Dart is a C corporation with average annual gross receipts in excess of $20 million for the last three years (all of its sales are via credit card, which is turned into cash immediately; thus, gross receipts for the year are over $20 million). The fourth requirement above indicates that accrual method of accounting for tax purposes is required if a C corporation has annual average gross receipts in excess of $5 million for the three-year period ending with the tax year-thus, Dart must use the accrual method of accounting for tax purposes.

Choices "a", "c", and "b" are incorrect, per the above explanation.