A company requires employees to create a $4$-digit passcode using the digits $0$ through $9$. The same digit can be repeated, and the digits must be entered in a specific order to unlock the system.
Is it appropriate to call this a 'combination' code? Why or why not?

• A. Yes, because the digits are chosen without regard to order.
• B. No, because the digits must be entered in a specific order.
• C. Yes, because repetitions are allowed.
• D. No, because only one digit is used at a time.

Answer: (B)