Which statement is correct regarding accounts receivable (A/R)?

a. A low number of days in A/R typically indicates successful revenue cycle management. 

b. A high number of days in A/R typically indicates successful revenue cycle management. 

c. The days in A/R is not reflective of the success of revenue cycle management.

d. The days in A/R is calculated using the oldest balance in days and the number of insurance carriers accepted by the practice