Final answer:
A Money Market Fund is a type of mutual fund that invests only in low-risk securities, providing investors with a safe place to maintain easily accessible, liquid funds with a minimal amount of risk and typically slightly higher returns than a regular savings account.
Step-by-step explanation:
The question asks us to identify a type of mutual fund that invests only in low-risk securities. From the options provided, the correct answer is D. Money Market Fund. A money market mutual fund is an investment vehicle that pools money from various investors to purchase low-risk, highly-liquid financial assets such as government bonds, certificate of deposit (CD), commercial paper, and other cash equivalent securities. It differs from other options like CD, which is a time-bound deposit with a bank that offers a fixed interest rate, or other investment accounts, which may not be strictly low-risk or may not be mutual funds. These funds aim to provide investors with a safe place to invest easily accessible, liquid funds with a minimal amount of risk involved, while often offering returns slightly higher than those of a regular savings account.