Western Governors University (WGU) ICSC2100 C949 Data Structures and Algorithms I Practice Exam

The data structure that follows the Last In First Out (LIFO) principle is a stack. In a stack, the most recently added item is the first one to be removed, which forms the essence of the LIFO principle.

This behavior can be easily visualized by considering how a stack of plates works; the last plate placed on top is the first one that can be taken off. Operations commonly associated with stacks include "push," which adds an element to the top of the stack, and "pop," which removes the top element. This structure is widely used in programming for functions like expression evaluation, backtracking algorithms, and maintaining the state of a program (such as during function calls).

The other data structures mentioned have different operational principles. For instance, a queue follows the First In First Out (FIFO) principle, where the first element added is the first one to be removed. An array is a static data structure that can store elements in indexed positions, while linked lists consist of nodes that can be connected in a linear fashion but do not inherently enforce a LIFO structure. Thus, the unique characteristic of a stack makes it the correct answer in this context.