Life cycle of a butterfly (chronological): Arrange — a. Butterfly, b. Cocoon, c. Egg, d. Worm (larva/caterpillar).

Introduction / Context:
Biological sequence questions test basic life science knowledge. Here you must order the metamorphic stages of a butterfly from beginning to end.

Given Data / Assumptions:

• Stages: Egg → Larva (caterpillar/worm) → Pupa (cocoon/chrysalis) → Adult (butterfly).
• We use the common terms provided in the options.

Concept / Approach:
Butterflies undergo complete metamorphosis with four distinct stages: egg, larva, pupa, adult. The question recasts these with the labels c, d, b, a respectively.

Step-by-Step Solution:

Verification / Alternative check:
Matches the canonical metamorphosis cycle taught in basic biology.

Why Other Options Are Wrong:
They misplace the pupa stage or start with the adult.

Common Pitfalls:
Confusing cocoon with larval stage; forgetting that adult is the final stage.

Final Answer:
c, d, b, a