access to iron ore and coal spurred the development of

a. livestock trade

b. the reaper

c. steel mills

d. grain elevators

C. steel mills , as they are an industrial plant that function in the basis if the ion ore and the use of the locals. The principle matter iron ore, limestone, and coal (or coke).

Explanation:

Since the invention of the steel mills they have replaced the ironworks based on the nowadays the steel is produced from the scraps and the liquid iron and the large blocks are cast and formed as due to the energy cost is associated with the heating and cooling a blast furnace. Originally the mill was adapted to the bar products such as the flats, channel and angles as the adjacent of the technology took place of the 198th energy i.e the industrial revolution mechanization of the manufacturing sector also gained momentum.

Answeroil-shale;