Stream terraces form as the result of which of the following processes?

1. Extremely rapid downcutting associated with a drop in sea level produces stream terraces.

2. Downcutting associated with a rise in sea level produces stream terraces.

3. The formation of meander scars leads to the development of stream terraces.

3. Extreme meandering as the land subsides leads to the development of stream terraces.

4. Downcutting following the rise of the landscape produces stream terraces.

Which is true?