Question

the national revolutionary party boosted the mexican economy by
privatizing the railroads and oil industry.
nationalizing the railroads and oil industry.
selling the railroads and oil industry.
closing the railroads and oil industry.

Explanation:

The National Revolutionary Party (PNR) in Mexico took steps to strengthen the nation's economic sovereignty. Nationalization means bringing industries under state control. By nationalizing the railroads and oil industry, the PNR could better manage these key sectors for the benefit of the Mexican economy. Privatizing would transfer control to private entities (often foreign), selling would also mean loss of state - held assets, and closing would be detrimental to economic activity.

Answer:

nationalizing the railroads and oil industry.