Why it is important for steel to go through a fluid phase as it is being produced.?

It is important to go through a fluid phase as it is being produced because the object must go through heat to be melted and then it should be put into a mold to be formed. Also, it go though heat to keep it from cracking and go to be cooled and harden. Hope this answers the question. Have a nice day.

Its either a) or b),wind and water erosion gradually widen the canyon