Category grouping: “Pen : Pencil : Ink — these items are best classified under which category?”. Choose the most precise umbrella term.

Introduction / Context:
This classification problem asks for the category that best groups pen, pencil, and ink. These are writing implements and supplies typically sold together as office or school supplies.

Given Data / Assumptions:

• Pen and pencil are writing instruments.
• Ink is a writing supply used by pens or for fountain pens.
• We need a precise categorical label.

Concept / Approach:
Among available options, “Stationery” specifically denotes writing instruments, paper, and related office/school supplies.

Step-by-Step Solution:
1) Identify item types: implements/supplies for writing.2) Map to category: stationery.3) Select the most specific umbrella term among choices.

Verification / Alternative check:
“Writing” is an activity, not a product category label; “Education/Teaching/Office” are broader contexts, not precise categories for the objects.

Why Other Options Are Wrong:

• Education/Teaching: Domains of activity, not product categories.
• Writing: An activity; too abstract.
• Office: A place/context, not the category name for the items.

Common Pitfalls:
Choosing an activity or context instead of the product category.

Final Answer:
Stationery