It is pointed out in the passage that the sharp rise
in oil prices in 1973 ____ .

Nigeria is heavily dependent on the export of crude oil
to finance industrial development. 90% of Nigeria's
exports by value are crude oil. At current production
rates, known reserves are only sufficient until the end
of the century. Industrialisation was boosted after I973
following the fourfold increase in oil prices. In the
early 1980s prices fell, and Nigeria lost important
income. Oil production peaked in 1974 when output
reached 112 million tonnes.