Scientists have discovered that the inner core of Earth is a solid while the outer core is a liquid. What is the cause of this observation?
Group of answer choices
1. The outer core has a higher temperature and more pressure than the inner core
2. The outer core has a lower temperature and lower pressure than the inner core
3. The inner core has a lower temperature and higher pressure than the outer core
4. The inner core has a higher temperature and lower pressure than the outer core