Multi-choice problem: Continue writing the next sentence in this paragraph:

How to improve mind power
Learn new skills.
By learning new skills, you keep your brain engaged and challenged, which can build new neural connections and improve your cognitive function.
Learning a new language is an excellent way to expand your mind.

Select from the following.
1). Your brain will learn new strategies and skills, and learning new skills can strengthen your cognitive skills. Getting out in social situations will also help you make changes to your attitude.;
2). Learning how to think without a foreign object in your environment will improve your mental well-being. Learning new techniques can also strengthen your sense of self.;
3). It will force your brain to work in ways it isn't accustomed to and can help you see the world around you from a new linguistic perspective. Trying new activities or hobbies can also help keep your brain tuned up.;
4). Learning new skills helps give you new ideas, expand your cognitive functions, and make you more vulnerable to learning new information. Learn new academic topics and becoming a more knowledgeable reader.;
3).