The Best of America marketFLEX II Annuity from Nationwide is a deferred variable annuity. The annuity has a variable rate of return based on the performance of a wide range of investment options you make. The growth of your annuity is tax deferred, which means you don't pay taxes until you start getting income. Another perk is a death benefit for beneficiaries. The advantage of the marketFLEX annuity is the ability to reallocate assets based on certain market signals.