It is B Population overcrowding Europe
Answer:
The steppe crosses the Russian plain, south of the taiga, penetrating deep into Siberia. It comprises three main types, which run in roughly parallel bands from east to west: forest steppe in the north, through steppe, to semi -desert steppe in the south. Within these belts, zones of temporary inundation on floodplains or in zones of internal drainage provide valuable hay land. The steppe was increasingly ploughed for crops during the twentieth century; initially crops were rotated with naturally regenerated grassland, but from mid-century cultivation was increasingly intensive. During the collective period, the emphasis was on industrial stock rearing, with housed cattle and high inputs; since decollectivization, intensive enterprises are closing for economic reasons, and systems have yet to stabilize. If ploughed land is left undisturbed it will return naturally to steppe vegetation in six to fifteen years. Hay is very important for winter feed, and much is made from seasonally flooded meadows. Many marginal, semi-arid areas of the steppe have been put under crops, but are not economically viable; much of the cereals so produced are fed to livestock, but grain yields are very low and yield no more livestock products than would natural grassland, but at far higher cost. Marginal cropland should return to grass.
Answer:
I think b is the correct answer
Embracing an area more than half a million square miles, the kingdom of Mali was undoubtedly one of the richest and most prosperous on earth in the 14th century. Its territory touched the Atlantic Ocean to the west and extended as far as the bend in the Niger River to the east. From north to south, it embraced the entire swath of land south of the Sahara to the thick tropical forests of equatorial Africa. The kingdom was richly endowed with gold, salt, cola nuts, and ivory, which were in great demand in the markets of the Mediterranean. But above all, it was endowed with gifted and far-sighted rulers like Mansa Musa.
From our perspective, the important element in Mali was that it was Muslim. This fact made it an integral part of the vast Islamic world. Trade and ideas flowed freely between Mali, North Africa, Spain, Egypt and Arabia. Muslim traders plied the desert with their caravans carrying brass work from Spain, brocades from Egypt, precious stones from India and returned with gold, salt, cola nuts, and ivory. More important was the flow of ideas and scholars. Africans traveled to Mecca for Hajj and brought back books written in Baghdad, Cairo, and Kairouan. Islamic jurists and ulema were in great demand in the learning centers of Sijilmasa, Timbuktu, Mali, and Ghana. African soldiers were very much a part of Muslim armies in Spain, Egypt, and India. Mali was thus a part of the Islamic mosaic contributing its wealth and its resources to the prosperity of Asia and Europe alike.
Reducing government spending.
