Butterfly life cycle — arrange metamorphosis stages from egg to adult: (a) Butterfly (b) Cocoon (c) Egg (d) Worm (caterpillar)

Introduction / Context:
This question concerns complete metamorphosis in butterflies and moths. The sequence begins with the egg and ends with the adult butterfly, with larval and pupal stages in between.

Given Data / Assumptions:

• Stages: Egg → Worm (caterpillar/larva) → Cocoon (pupa/chrysalis) → Butterfly (adult).
• We adopt common classroom terminology where “worm” stands for “caterpillar.”

Concept / Approach:
Butterflies undergo holometabolism: distinct egg, larva, pupa, and adult phases. The caterpillar feeds and grows; the pupa is a transformative stage; the adult emerges to reproduce.

Step-by-Step Solution:
1) Egg (c) — laid on host plants.2) Worm/caterpillar (d) — feeding and growth stage.3) Cocoon/chrysalis (b) — metamorphic transformation.4) Butterfly (a) — reproductive adult.

Verification / Alternative check:
Standard biology diagrams match this order exactly.

Why Other Options Are Wrong:

• Any option starting with adult or cocoon is out of order.
• Sequences that place egg later violate the life-cycle start.

Common Pitfalls:
Confusing cocoon (covering) with chrysalis; in many butterflies the pupal case itself is the chrysalis. The educational order remains unchanged.

Final Answer:
c, d, b, a