<h2>Hello!</h2>
The answer is: D. Coal
<h2>
Why?</h2>
Coal power plants burn coal in to get steam, the steam flows into a turbine which is coupled to an electrical generator.
Coal power plants work burning high amounts of coal into a boiler, generation a lot of steam under extreme pressures. The steam is obtained when the water is heated by the burning coal, then the steam is cooled, being transformed in liquid water again (due the condensation process) and it's sent back on a cyclical process.
Have a nice day!
Answer:

Explanation:
Given:
mass of first particle, 
mass of second particle, 
mass of third particle, 
coordinate position of first particle in meters, 
coordinate position of second particle in meters, 
coordinate position of third particle in meters, 
<u>Now, gravitational force on particle 3 due to particle 1:</u>



towards positive Y axis.
<u>gravitational force on particle 3 due to particle 2:</u>



towards positive X axis.
<u>Now the net force</u>



<em>For angle in counterclockwise direction from the +x-axis</em>

The physical law that explains that is the law of conservation of energy which states that he energy of an isolated sistem remains constant