Final answer:
The correct answer is D. These are all good ways to stay diversified, including investing in ETFs, mutual funds, and regular portfolio re-balancing to ensure investments align with risk tolerance and goals.
Step-by-step explanation:
Staying diversified is a method financial investors use to spread out their investment risk across different types of assets such as stocks, bonds, and mutual funds. While investing only in ETFs or mutual funds can be a way to achieve diversification, since these funds themselves invest in a variety of assets, they are not the sole ways to maintain a diversified portfolio. Regular portfolio re-balancing every few months is also essential in maintaining diversification because it ensures that investments stay aligned with one's risk appetite and investment goals. It avoids any one investment becoming too significant a part of the portfolio due to market changes. Therefore, D. These are all good ways to stay diversified is the correct answer, as it encompasses all mentioned methods of maintaining a diversified investment strategy.