Which one of the following elements is alloyed with iron to produce steel which can resist high temperatures and also have high hardness and abrasion resistance ?

Tungsten is the alloying element used in steels that need outstanding hot hardness, high hardness and abrasion (wear) resistance. Tungsten is a principal component of high‑speed and tool steels, where it forms hard carbides and stabilizes microstructure so the steel retains hardness and wear resistance even at elevated temperatures; such tungsten-containing steels are explicitly noted for their heat- and wear-resistance and are often called tungsten or tungsten-containing high‑speed steels. Detailed studies of tungsten in steel show it increases carbide volume and hot (red) hardness and is used in hot‑work and tool steels for high‑temperature strength and abrasion resistance.