The color of the light changes in the scenario because a volcano erupts. The light is the variable.

When the color of the light changes, the number of light red walking beans will also change. The population of light red walking beans is therefore the variable.

i think that the right answer is the aztecs

europeans carried a hidden enemy to the indians: new diseases. native peoples of america had no immunity to the diseases that european explorers and colonists brought with them. diseases such as smallpox, influenza, measles, and even chicken pox proved deadly to american indians

d is definitely the answer