In data structures, which of the following is an example of a linear data structure where elements are arranged in a sequence?

Introduction / Context:
This question tests basic knowledge of data structure classification. Data structures can be broadly divided into linear structures, where elements are arranged in a sequence, and non linear structures, where elements have more complex relationships such as hierarchies or networks. Understanding which common structures belong to each category helps learners choose appropriate tools for algorithms and is frequently tested in computer science exams at school and undergraduate levels.

Given Data / Assumptions:

• The topic is the classification of data structures as linear or non linear.
• Options include tree, binary tree, queue, graph and heap.
• We assume standard textbook definitions of these structures.
• The question asks which structure is linear, meaning elements are logically in a sequence.

Concept / Approach:
In a linear data structure, elements form a sequence where each element (except the first and last) has a unique predecessor and successor. Examples include arrays, linked lists, stacks and queues. In non linear data structures, elements can have multiple relationships, such as parent child and many connections. Trees, binary trees, graphs and heaps fall into the non linear category. A queue is a linear structure that follows first in first out order, where elements are added at one end and removed from the other. Therefore, queue is the only option from the list that is clearly a linear data structure.

Step-by-Step Solution:

Verification / Alternative check:
Data structures textbooks and course notes clearly categorise arrays, lists, stacks and queues as linear structures. They describe trees and graphs as non linear because nodes can branch to multiple children or neighbours. Heaps are a special kind of tree used for priority queues and are therefore non linear as well. Teaching examples often use the analogy of people standing in a queue to explain the behaviour of the queue data structure, reinforcing its linear nature. These consistent classifications across authoritative sources confirm that queue is the correct answer to this question.

Why Other Options Are Wrong:

• Tree: A non linear structure with hierarchical relationships between nodes.
• Binary tree: A specific type of tree where each node has up to two children, still non linear.
• Graph: A non linear structure where nodes can have many edges connecting them in complex ways.
• Heap: A specialised tree based structure used in priority queues, classified as non linear.

Common Pitfalls:
Because queues and trees are both frequently discussed, learners sometimes mix up their categories. A helpful memory aid is to picture a queue as a straight line of elements, reflecting its linear nature, while a tree looks like a branching diagram. Another pitfall is thinking that binary trees are linear because of the word binary, but the number of children does not change the fact that it is a branching structure. When a question explicitly asks for a linear data structure among options that include trees and graphs, queue is usually the correct choice.

Final Answer:
The linear data structure among the options is the Queue.