D. The accepted interpretations about past events can change greatly over time
People in the south used slaves because their economy was focussed on things like cash crops (tobacco, cotton, etc.) These crops required a lot of work so farmers and plantation owners could not do it by themselves. So by using enslave persons they could harvest more crops, sell more, make more money, and in return boost the southern economy.
Political map
Political maps are designed to show governmental boundaries of countries, states, and counties, the location of major cities, and they usually include significant bodies of water.
The best answer would be "Using the atomic bomb would change the world forever by making it a more dangerous place."