They became extinct in that region, and grew in a hotter region.
Answer:
D. Reversal of Earth's magnetic field
Explanation:
The earth's magnetic field changes over time and this causes changes in the direction of magnetization of magnetic elements or minerals in rocks.
Our magnetic field is widely believed to originate from activities within the outer core where molten iron and nickel moves. The flow of these molten elements results in the production of the magnetic signatures on earth surface.
Some elements and minerals within rocks are capable of recording the direction of magnetic fields at a period in time. Before magma cools, such minerals in these rocks aligns their poles to that of the prevailing direction of the earths magnetic field. This is how the magnetic changes at the mid-oceanic ridges are recorded.
A large part of that land area is not conducive to farming or general use. The Canadian Shield covers about a third of the nation. The Arctic permafrost probably covers another third. You cannot farm in either of these areas and the cost of building roads and infrastructure in or through these areas is very high. Other areas have land that could be used for farming but the season is too short. On the lands that are arable, Canadians are reasonably densely populated.
<span>As to softened immigration process, the percentage of permanent residents (generally recent immigrants) has remained fairly steady at less than or at 1% of the population for at least 50 years. Since the birthrates for multi generational Canadians (Canadians whose grand parents or before were immigrants) is so low, Canada needs immigrants to maintain the population at a sustainable level. Yet the processes have not gotten easier. The most recent iteration of the Immigration act has extended the time required for a landed immigrant to live in Canada before being eligible for citizenship (from three years in five to four years in six).</span>
