What kind of attack is performed by an attacker who takes advantage of the inadvertent and unauthorized access built through three succeeding systems that all trust one another?
a. privilege escalation
b. cross-site attack
c. horizontal access attack
d. transverse attack

(A) Privilege escalation

Explanation:

 Privilege escalation is one of the type of attack that is typically perform by an attacker for the purpose of designing the flaws and also helps in exploiting the bugs in the different types of software applications and also the operating system.

According to the given question, the privilege escalation is the term which is used for describe about the various types of advantages for unauthorized accessing to different types of resources ion the system.        

 Therefore, Option (A) is correct answer.