Explanation:
♤decay of radioactive elements
♤ leftover heat from planetary formation
♤heat released as the liquid outer core solidifies near its boundary with the inner core.
Considering the available options, the discovery responsible for the shift from rural to urban population is the "<u>Electricity</u>."
<h3>What is Shift from Rural to Urban Population?</h3>
The Shift from Rural to Urban population is the increase in the population of the urban centers due to migration from the rural areas.
Following the discovery of electricity, there is a rise in industrialization, thereby leading to people migrating from rural areas to urban areas to get jobs and live better lives.
Hence, in this case, it is concluded the correct answer is option D. "Electricity."
Learn more about the impact of electricity here: brainly.com/question/16620781
Hello! It is helpful to know what each of these lines are... First of all, we can cancel out D because it is not even a line connecting anything! We can then cancel out C because parallel lines are line side by side but do not touch or connect in any way. The lines of latitude do run north to south and east to west, however, it is parallel to the equator. So we can cancel out B. Which leaves us with A! Lines of latitude runs east and west of the Prime Meridian, and connects the north and south poles!
I hope this helped!
I am, yours most sincerely,
SuperHelperThingy