Classification — writing tools vs reading materials: select the item that is NOT of the same “type” as the others.

Introduction / Context:
Here, the items mix tools and artifacts. Three options are stand-alone artifacts or tools; one is a component (a part of another item). We need the unique “part-of” rather than “whole/tool”.

Given Data / Assumptions:

• Pen → writing instrument (whole object).
• Pencil → writing instrument (whole object).
• Book → complete object.
• Page → component of a book (part, not a whole stand-alone in ordinary use).

Concept / Approach:
Identify the sole “part” among wholes/tools.

Step-by-Step Solution:
1) Pen/Pencil/Book → whole artifacts.2) Page → component inside a book.3) Therefore “Page” is the odd one out.

Verification / Alternative check:
Ask: which item naturally “belongs to” another item? Only page is inherently contained in a book.

Why Other Options Are Wrong:
They are independent objects, not components.

Common Pitfalls:
Pairing pen/pencil as tools vs book as material; while true, “page” is the only part-of relation, making it the strict outlier.

Final Answer:
Page