Final answer:
The unrecovered investment in an annuity can be deducted from the taxpayer's final income tax return when the taxpayer dies before fully recovering the investment.
Step-by-step explanation:
When a taxpayer dies before fully recovering their investment in an annuity contract, the tax consequences are specific. Under current tax law, if the annuity owner dies before they have recovered their investment in the annuity, the excess of the amount invested over what was received tax-free is deductible on the deceased taxpayer's final income tax return. This means that answer option 'c' is correct: The amount of the unrecovered investment is deducted from the taxpayer's final income tax return.