Step 1: Understanding the question.
The question asks for the estimated pressure and temperature at the center of the Earth. This information is critical in understanding the conditions that exist deep within the planet.
Step 2: Analyzing the options.
(A) 360 GPa, 2600 K: Incorrect — The temperature at the Earth's core is estimated to be higher than 2600 K.
(B) 450 GPa, 6000 K: Incorrect — The pressure at the Earth's center is closer to 360 GPa, not 450 GPa.
(C) 360 GPa, 6000 K: Correct — The pressure is around 360 GPa and the temperature at the Earth's core is estimated to be around 6000 K.
(D) 450 GPa, 2600 K: Incorrect — The pressure is too high, and the temperature is too low for the Earth's center.
Step 3: Conclusion.
The correct answer is (C) 360 GPa, 6000 K, as these are the commonly accepted estimates for the Earth's core conditions.