Final answer:
The savings account is the best option for earning interest while having the flexibility to withdraw funds anytime without penalties. The correct answer is option c).
Step-by-step explanation:
The account option that allows the account holder to earn interest on their money while allowing funds to be withdrawn at will without a fee or penalty is the savings account. While a certificate of deposit (CD) offers higher interest rates, it does not allow for flexibility in withdrawal without incurring a penalty. A checking account, on the other hand, typically offers easy access to funds with little or no interest, and a money market account may have limitations or requirements for minimum balances or transaction numbers.