The correct answer to the questions is : Title 1 should be outer planets and title 2 should be inner planets.
EXPLANATION:
All the planets in our solar system are classified into two categories which are known as outer planets and inner planets.
The inner planets are the planets which come before the asteroid belts .There are four inner planets i.e Mercury, Venus, Mars and the earth.
The inner planets are closer to the sun.They have shorter year, and made up of rocks.
The outer planets come after the asteroid belts. They are farther away from the sun.They have long duration of revolution, and are generally made up of gas.
For instance, Jupiter, Neptune, Saturn and Uranus.
Hence, the title 1 is for outer planets and title 2 is for shorter planets.