<span>The depression at the top of the volcano is called as a crater. It is roughly circular, and possesses one or more vents. At the time of volcanic eruptions, the magma and the lava are erupted from the crater itself. The crater may also break during eruption, and such craters have a lower rim on one side of the volcano.</span>
People migrate for a number of reasons. These reasons may fall under these four areas: Environmental, Economic, Cultural and Socio-political. ... Poor economic activity and lack of job opportunities are also strong push factors for migration.
The correct answer is - A) subsistence farming.
Subsistence farming is the type of farming that is mostly practiced in the less developed countries. In here we have production that is just about enough for the needs of the country (and big portion of the production doesn't even come out on the home market, but you eat what you produce, or trade with someone you know). Also this type of farming is still based on primitive tools and is heavily dependant on the climate, and that makes it very unstable and more often than not people are starving because not enough food has been produced.
D. Rolling hills . Its usally Plateu but I gusse rolling hills would work too
