Which of the following is MOST similar between the inner and outer core of the Earth?

a.)composition
b.)pressure
c.)movement
d.)density

B. Pressure

The correct answer is d.) density. The inner and outer core of the Earth, both being part of the Earth's core, have a similar density.

To determine which option is most similar between the inner and outer core of the Earth, we need to analyze each option.

a.) Composition: The inner core is primarily composed of solid iron, whereas the outer core is composed of liquid iron and nickel. Therefore, the composition of the inner and outer core differs, making this option incorrect.

b.) Pressure: Both the inner and outer core experience high pressure due to the weight of the Earth's layers above them. This pressure is responsible for maintaining the outer core as a liquid despite its high temperature. Consequently, the pressure is similar between the inner and outer core, so this option is a possibility.

c.) Movement: The outer core experiences convection currents, which generate movement and create the Earth's magnetic field. In contrast, the inner core remains motionless. Therefore, the movement in the inner and outer core differs, making this option incorrect.

d.) Density: The inner core has a higher density compared to the outer core due to its solid state. The outer core, being liquid, has a lower density. Thus, the density between the inner and outer core differs, making this option incorrect.

Analyzing the options, we find that pressure is the most similar between the inner and outer core of the Earth. Therefore, the correct answer is b.) pressure.