Pierce Products, Inc. sponsors a postretirement plan providing health care benefits to employees who have completed at least 10 years service and are age 53 years or older at retirement. To date, the employees that have retired under the plan have an average age of 60. No employee has worked beyond age 65. Taranda was hired when she was 46 years old. The attribution period for accruing Pierce's expected postretirement health care benefit obligation to Taranda is during the period when Taranda is:
a. 53 to 60 years old
b. 53 to 65 years old
c. 46 to 56 years old
d. 46 to 65 years old