Which of the following statements is not true? (Assume standard computer science usage: a tree is hierarchical, pointers traverse a linked list, and a checksum digit detects transmission errors.)

Introduction / Context:
Many foundational terms in computer science have standard meanings: trees form hierarchical structures; pointers enable traversal of linked lists; and checksum digits help detect errors in transmission or storage. To answer which statement is not true, we verify each claim against these accepted definitions.

Given Data / Assumptions:

• Tree data structures represent parent–child hierarchies.
• Linked lists consist of nodes referenced by pointers or links.
• Checksums provide basic error detection for data integrity.

Concept / Approach:
Evaluate each statement for correctness. If (a), (b), and (c) are all true, then no statement among them is false. Therefore, the correct selection for “which is not true” is “None of the above,” because none are false.

Step-by-Step Solution:
1) Trees as hierarchical: true—rooted structures with levels and parent–child relations.2) Pointers and linked lists: true—next references enable sequential traversal and updates.3) Checksum digit: true—e.g., parity bits, CRCs, and Luhn-like digits detect errors.4) Since (a)–(c) are true, the “not true” option must be “None of the above.”

Verification / Alternative check:
Introductory data structures and networking texts confirm these definitions; checksums are ubiquitous in protocols and storage.

Why Other Options Are Wrong:
All of the above: choosing this would assert (a)–(c) are not true, which is incorrect.Any single option (a–c): each is a correct statement, not a false one.

Common Pitfalls:
Misreading “not true” questions; overlooking that “None of the above” fits when all listed statements are correct.

Final Answer:
None of the above