how to calculate accumulated other comprehensive income (AOCI)

Question

The following information relates to the pension plan for the employees of Turner Co.

                                                                           1/1/12                   1/1/13                         1/1/14

Projected benefit obligation                           2,790,000                 2,988,000                   4,002,000

Fair value of plan assets                                 2,550,000                 3,120,000                 3,444,000  

AOCI- net (gain) or loss                                         0                       (432,000)                 (480,000)

Settlement rate (for year)                                                                        11%                       11%

Expected rate of return (for year)                           8%                           7%

Turner estimates that the average remaining service life is 16 years. Turner's contribution was $378,000 in 2013 and benefits paid were $282,000.

To calculate the amount of AOCI (net gain) amortization in2013, the corridor we should use is

a. 10% of 2,988,000.

b. 10% of 3,120,000

c. 10% of 3,444,000

d. 10% of 4,002,000