rivers rising due to storms and floods evaporation of water from the leaves of a plant weathering of a rock to form small rocks and sand movement of small pieces of rock by flowing water
I gave my students this multiple choice question: Some events on Earth happen instantly while others take thousands of years to occur. Which process takes the longest time to complete?

Only one answer is correct among these 4 choices:
- rivers rising due to storms and floods
- evaporation of water from the leaves of a plant
- weathering of a rock to form small rocks and sand
- movement of small pieces of rock by flowing water

Could you tell me which one is correct?

weathering of a rock to form small rocks and sand