The correct answer is D. All of the above.
Strategic industries are those that are essential to the national security and economic well-being of a country. They are typically industries that are involved in the production of goods or services that are critical to the functioning of the economy or the military.
The industries listed in the question are all considered to be strategic industries. Industries related to equipments for safety and power generation are essential to the functioning of the military and the economy. Electricity, road and steel industries are essential to the infrastructure of a country. Industries related to railway and mineral products are essential to the transportation and manufacturing sectors of the economy. Health and education related industries are essential to the well-being of the population.
Therefore, all of the industries listed in the question are considered to be strategic industries.