Selected pension data for Rotman Company for 2018 were as follows:
- PBO, January 1: $240,000
- PBO, December 31: $270,000
- Pension plan assets (fair value) January 1: $180,000
- Pension plan assets (fair value) December 31: $230,000
The projected benefit obligation was underfunded at the end of 2018 by:

- $30,000
- $60,000
- $20,000
- $40,000