Revenue is the gross inflow of economic benefits during the period arising from the course of the ordinary activities of an entity when those inflows result in increases in equity, other than increases relating to contributions from equity participants. In other words, revenues are earnings that result from delivering goods or services to customers. In this sense, revenues are the gross increase in owner’s equity resulting from business activities entered into for the purpose of earning income. For examples, selling goods (sales), performing services (fees), lending money (interest), leasing machine (rent) all create revenues for a given period. A is the right answer.