Answer:
d. hybrid attack
Step-by-step explanation:
Hybrid attack is basically the combination of dictionary attack and brute force attack and its names depicts that its a mixture of two attacks.
Dictionary attack is mechanism in which the password is cracked by trying as a password, every word in a dictionary in order to crack the password and enter a computer. As most of the and also the new users often use simple words as passwords which can also be found in a dictionary so breaking such passwords is easy using this technique.
Brute Force attack is basically making several attempts to crack a password. This technique of making multiple attempts and multiple combinations of passwords until the correct passwords is guess is called trial and error method.
Now hybrid attack is the combination of both brute force and dictionary attacks. So it uses a dictionary which provides a word list and then applies brute force on this word list which will modify dictionary words a little by adding brute force key space to the end of these words such as appending numbers, misspelling words or appending special characters. For example new employees less aware about the password attacks, kept their names as a password. So hybrid attack can be used by attacker/hacker to crack such passwords by obtaining a list of names of all new employees in the company. Then the attacker can apply a brute force attack to the end of each name to crack the password.