One moon-phase cycle One ocean-tide cycle An acorn growing into an adult tree A caterpillar becoming a butterfly
I gave my students this multiple choice question: Which of these will take the LONGEST time to observe?

Only one answer is correct among these 4 choices:
- One moon-phase cycle
- One ocean-tide cycle
- An acorn growing into an adult tree
- A caterpillar becoming a butterfly

Could you tell me which one is correct?

An acorn growing into an adult tree