Pen : Write :: Knife : ?

**The reasoning** This is an **analogy question** — it tests your ability to see relationships between words. The format is: "A is to B as C is to D" (A : B :: C : D) Here's the key: **What does a pen DO?** A pen *writes*. That's its primary function or purpose. So the question asks: **What does a knife DO?** A knife *cuts*. That's its primary function. We're looking for the **action/function relationship**, not a description. Pen performs the action of writing, just as knife performs the action of cutting. **Why the wrong options tempt you** - **A) Sharp** — This describes what a knife *is like* (a quality), not what it *does*. Same trap as saying "Pen : Black" instead of "Pen : Write" - **C) Long** — Another description/property, not a function - **D) Metal** — Describes what it's *made of*, not its purpose **Quick takeaway** In analogy questions, match the *type* of relationship: if the first pair shows **object → action**, the second pair must too — not object → description or object → material.