Final answer:
The key factor to determine when Nguyen and Marissa will have the same amount of money in their savings accounts is the interest rate.
Step-by-step explanation:
The key factor to determine when Nguyen and Marissa will have the same amount of money in their savings account is the interest rate (D).
- Initially, they may have different savings amounts (A), monthly withdrawal amounts (B), and monthly deposit amounts (C).
- However, the interest rate will determine how fast their savings grow over time.
- If both Nguyen and Marissa have the same interest rate, their savings will eventually reach the same amount after a certain period of time.