The block absorbs all blue light. The block bends (refracts) all blue light. Only blue light is reflected by the block. Only blue light passes through the block.
I gave my students this multiple choice question: What causes a blue block to appear blue in the sunlight?

Only one answer is correct among these 4 choices:
- The block absorbs all blue light.
- The block bends (refracts) all blue light.
- Only blue light is reflected by the block.
- Only blue light passes through the block.

Could you tell me which one is correct?

Only blue light is reflected by the block.