The correct answer is A) oil.
The natural resource that was discovered in the late 1800s before Oklahoma became a state, significantly increasing the value of the land was oil.
Oil Exploration companies established in the Indian territory in 1897. The news that oil had been found in Bartlesville, near Caney River, south of the Kansas border, spread rapidly. That was the first Oklahoma oil well. In 1901, Red Fork Gusher drilled more wells in Tulsa, Oklahoma. After exploiting many more wells in the region, the company became the Cahege Oil and Gas Company.
