Would you rather receive $80/year for 20 years, or $50/year forever assuming a 15% discount rate?

Your company pension fund owes $1,000,000 per year for the next 20 years. They currently own 11.5 million 5-year bonds with a 6% coupon priced at par. Analyze the value of the pension funds assets and liabilities if interest rates go up or down 100 basis points or stay the same. What alternative investment would you recommend given this sensitivity analysis?