What are convection currents in the mantle caused by? A. The core heats up magma and increases its density, so it rises,
B. The core heats up magma and decreases its density, so it rises,
C. The core cools down magma and increases its density, so it rises,
D. The core cools down magma and decreases its density, so it rises.

The human activities in two locations are described below: location a: rampant use of plastic containers location b: excessive use of pesticides and fertilizers which statement is most likely true? location a will have poor air quality because plastic is biodegradable. location a will experience water scarcity because plastic absorbs moisture. the population of honeybees will increase in location b because production of crops will increase. the population of fish in location b will decrease because the water is contaminated.