2. Millbrook Company maintains a defined benefit plan for its employees. In 2018, the company granted prior service cost (PSC) benefits to some employees which were valued at 530 million. The company properly included this amount in Other Comprehensive Income. The amount of amortization of the PSC for 2018 was calculated to be $5 million. Accordingly, the company should do what with respect to this amortization?
   1. Increase pension expense and the PBO
   2. Increase the PBO only
   3. Increase pension expense only
   4. Decrease pension expense only