Final answer:
Shelly should choose an interest-bearing checking account to earn some interest on her $100 while maintaining easy access to her money.
Step-by-step explanation:
A checking account would be best for Shelly to use if she wants to earn the most interest on her account while keeping only $100 in her account. Although checking accounts typically pay little or no interest, some banks offer interest-bearing checking accounts with certain conditions such as maintaining a minimum balance. By choosing a bank that offers an interest-bearing checking account and keeping $100 in her account, Shelly can earn some interest while still having easy access to her money through checks or debit cards.