A Local Medical Office Processed and Mailed 11,628 Bills to Patients

A local medical office processed and mailed 11,628 bills to patients last year. Find the average number of bills mailed each month?

A) $971$ pieces of mail per month
B) $973$ pieces of mail per month
C) $969$ pieces of mail per month
D) $966$ pieces of mail per month
E) $968$ pieces of mail per month