Final answer:
Contributions to a Roth IRA are taxed before they are made, meaning they are made with after-tax dollars, allowing investments to grow tax-free, and making the qualified withdrawals in retirement tax-exempt.
Step-by-step explanation:
With a Roth IRA, the contributory funds are taxed as income before the contributions are made. This means the answer to your question is b) Before. Contributions to a Roth IRA are made with after-tax dollars.
Unlike a traditional IRA where you make contributions with pretax income, in a Roth IRA, you pay taxes on the money when you earn it, so you won't have to pay taxes on your withdrawals in retirement as long as you follow the rules established by the IRS. Therefore, the main advantage of a Roth IRA is that it allows investments to grow tax-free, and the distributions in retirement are not taxed.