Finish the following sentence with the best choice: How to Make a Sponge Motorboat

Choices:
- To make a Sponge Motorboat, first build a propellor by cutting off a slice of cork from a wine bottle and push it on your motor spindle. Make sure it can spin freely.
- To make a Sponge Motorboat, first build a propellor by cutting off a slice of cork from a wine bottle and push it on your motor spindle. Make sure it is tight and can not spin.

Answer:
To make a Sponge Motorboat, first build a propellor by cutting off a slice of cork from a wine bottle and push it on your motor spindle. Make sure it can spin freely.