Two rods of the same shape are held at their centers and rotated back and forth. The red one is much easier to rotate than the blue one. What is the best possible explanation for this?

1. The red one has more mass.
2. The blue one has more mass.
3. The red one has its mass concentrated more toward the center, while the blue one has its mass concentrated more toward the ends.
4. The blue one has its mass concentrated more toward the center, while the red one has its mass concentrated more toward the ends.
5. Either 1 or 3
6. Either 1 or 4
7. Either 2 or 3
8. Either 2 or 4
9. Due to the nature of light, red objects are just inherently easier to spin than blue objects are.

It could be that the blue one has more mass, or that the mass distribution is different. In our case the rods actually have the same mass, but the mass is distributed differently. The red one has its mass concentrated toward the center, while the mass of the blue rod is mostly at the ends.