The concept of matching revenue and expense refers to the fact that:
a. expenses for a period equal the revenues for the period.
b. all costs incurred in the process of earning revenue during a period are recorded as an expense in that period.
c. all cash disbursements during a period are subtracted from all cash receipts during the period.
d. costs incurred in the process of earning revenue during a period are deferred and expensed in a future period.