Mark and Amanda conducted this experiment with two rocks that had the same color, luster, and hardness, but different color streaks. What can you conclude about these two rocks?

We can conclude that when rocks have streaks of different colors, the colors of the rocks are the same.

Explanation:

The colors of the rocks are inversely proportional to the streaks of colres they have. If two rocks have streaks of different colors it means that they will have equal colors. Likewise, if two rocks have streaks of different colors, it means that they will have the same colors. This is because the colors of the rocks depend exclusively on the absorption of the wavelengths that the minerals in the composition of the rocks may or may not absorb.

we need a diagram to you sorry

i would say b. research typically uses a variety of sources