Which of These Overestimates of Revenue Can Occur Within the Accounting

Multiple Choice

Which of these overestimates of revenue can occur within the accounting standards?

A) Shipping goods prematurely to buyers without a firm order and recognising revenue when the goods are shipped
B) Making estimates which later prove to be over-optimistic
C) Backdating sales made during the early part of the new accounting period to the last part of the old accounting period
D) A and B can occur within the accounting standards