Final answer:
You cannot contribute to an IRA for the previous year after April 15th, even with a tax filing extension. The deadline for IRA contributions is fixed and does not extend with the tax filing deadline.
Step-by-step explanation:
The question is whether you can contribute to an Individual Retirement Account (IRA) from the previous year after April 15th if you file an extension. The correct answer to this question is b) No, IRA contributions are not allowed after April 15th, irrespective of filing an extension. The deadline for making contributions to an IRA for a given tax year is the tax filing deadline, typically April 15th of the following year. This deadline does not change even if you file for an extension on your tax return. Therefore, while filing an extension allows you more time to submit your tax return, it does not extend the time you have to make IRA contributions for the previous tax year.