During July, Neptune Company Had Actual Sales of $144,000 Compared

During July, Neptune Company had actual sales of $144,000 compared to budgeted sales of $156,000. Actual cost of goods sold was $108,000, compared to a budget of $109,200. Monthly operating expenses, budgeted at $22,400, totaled $20,000. Interest revenue of $2,000 was earned during July but had not been included in the budget. In reviewing the report and related data, the manager may conclude:

A) the increase in sales was due to a one-time special order.
B) the interest revenue increase was related to a decrease in July's cash flows.
C) there is a scarcity of products available to be purchased.
D) none of the above.