Which statement is NOT true of the Middle Belt in Nigeria

The Middle Belt of Nigeria has long been described in geography texts by three linked features: much of its land has historically supported comparatively low population density, it lies within a zone affected by insect pests and disease-carrying vectors such as the tsetse fly, and large tracts of its soil have been regarded as less productive than the richer alluvial soils found elsewhere in the country, partly because of leaching and erosion on its plateau and highland surfaces.

These three characteristics are not independent of one another. The presence of disease-carrying insects historically discouraged both human settlement and livestock keeping across parts of the Middle Belt, which in turn kept population figures low; sparse population and limited investment in soil management then contributed to lower agricultural productivity on much of the land. Because every one of the three specific statements offered, low soil productivity, presence of insect pests and disease vectors, and sparse population, matches a genuinely documented feature of the region, none of them is the false statement being sought.

A question asking which statement is not true is only answered by picking out a genuinely false claim from among the ones listed. Here, since all three descriptive statements about the Middle Belt hold up against known geography, the only logically consistent conclusion is that none of the given statements is untrue.

When a question of this kind offers a choice indicating that no false statement is present among those listed, test each statement individually before selecting it; it is only correct when every other statement survives scrutiny as true.