<human>: Objective: How can you do sit ups without straining your neck?

Which of the following solutions is more sound in terms of naive physics reasoning?

OPTIONS:
- If you'll press your tongue against the roof of your mouth while doing sit ups it will stop you from straining your neck.
- If you'll press your foot against the roof of your mouth while doing sit ups it will stop you from straining your neck.
<bot>: If you'll press your tongue against the roof of your mouth while doing sit ups it will stop you from straining your neck.