Final answer:
Nonword passwords are vulnerable to a brute force attack, where the password cracker tries every possible combination of characters.
Step-by-step explanation:
A) Brute Force
Brute force attack is a type of attack where the password cracker tries every possible combination of characters to gain access to a password-protected system. Nonword passwords are highly vulnerable to such attacks because they do not contain real words or meaningful combinations of characters, making them easier to crack. In contrast, passwords like 'FLUFFY IS PUFFY' provide better security as they consist of a random mixture of letters and numbers.