Classification — animal class mapping: choose the pair that is factually incorrect.

Introduction / Context:
Three pairs correctly match an animal with its taxonomic class. One pair is incorrect: salamanders are amphibians, not insects.

Given Data / Assumptions:

• Whale → mammal (warm-blooded, live birth, mammary glands).
• Snake → reptile.
• Frog → amphibian.
• Salamander → amphibian (not insect).

Concept / Approach:
Validate each animal→class fact. Single factual mismatch is the odd pair.

Step-by-Step Solution:

Verification / Alternative check:
Amphibians include frogs, salamanders, newts; insects are arthropods with three body segments and six legs.

Why Other Options Are Wrong:
They are factually correct pairs.

Common Pitfalls:
Confusing “lives in water” with “fish/insect”; class is defined by anatomy and development.

Final Answer:
Salamander : Insect