The chart below shows the percentage of total government revenue from oil in nigeria between 1967 and 1990.
based on the information in the chart, what conclusion can be drawn about the oil industry in nigeria?
a: nigeria was generating less revenue from oil in 1987 compared to pervious years.
b: nigeria was generating greater revenue from oil in 1990 compared to previous years.
c: nigeria’s oil revenue peaked during 1975.
d: nigeria’s oil revenue decreased during 1987.