An analyst who has been scoping for arbitrage opportunities in dollar denominated Eurobonds have uncovered the following scenarios:

Yield on a regular bond is 7% and the yield on a callable bond is 6%

Yield on a regular bond is 7% and the yield on a puttable bond is 8%

You as the portfolio manager is to identify the arbitrage opportunity and advise the Board on which investment to make. You have to provide your logic in your decision making process (critical thinking). Will you recommend a regular bond, callable bond or the puttable bond? Why?