Which of the following is a major difference between Earth's inner core and outer core? A. The inner core is liquid, and the outer core is solid. B. The inner core is solid, and the outer core is liquid. C. The inner core is gas, and the outer core is solid. D. The inner core is solid, and the outer core is gas.

Step 1: Define the Problem

Identify the key components of the question that need to be addressed:

• Determine the major difference between Earth's inner core and outer core.

Step 2: Break Down the Problem

Divide the problem into smaller, manageable parts:

• Understand the state of matter of Earth's inner core.
• Understand the state of matter of Earth's outer core.

Step 3: Apply Relevant Concepts

Use appropriate academic theories or formulas to solve each part of the problem:

• Earth's inner core is known to be solid due to immense pressure.
• Earth's outer core is known to be liquid, which is responsible for Earth's magnetic field.

Step 4: Analysis, Verify and Summarize

Analyze each part in detail if necessary, carry out the calculations by steps. Verify the calculations result and summarize the findings:

• The inner core is solid, and the outer core is liquid.

Final Answer

Present the final result in a concise manner:

• B. The inner core is solid, and the outer core is liquid.