This treats the $4,000 customer advance and the $1,000 collection as revenue, even though only the separate $2,000 service was performed.
The credit service increases revenue by $2,000, the current utility service increases expense by $1,200, and the unperformed customer advance remains a $4,000 liability.
This measures revenue and expense correctly but omits the obligation created by the advance.
This records revenue when $1,000 is collected rather than when the $2,000 service is performed.
Answer: B
The $4,000 advance increases Cash and liabilities because no related work has been performed. The separate $2,000 service increases Accounts Receivable and revenue. Collecting $1,000 reduces the receivable and increases Cash without increasing revenue again. Paying $1,200 for current utility service increases expense. Revenue is $2,000, expense is $1,200, liabilities are $4,000, and equity is $800.