Final answer:
Nickel (d) is the alloying element in steel that provides corrosion resistance, being a key component in stainless steel variants due to its enhancement of durability against environmental corrosion.
Step-by-step explanation:
The element used as an alloying element in steel that provides corrosion resistance is nickel (d). Nickel enhances the material's ability to resist corrosion, making it a valuable component in the makeup of stainless steel. Steels are a class of alloys mainly composed of iron but also include carbon, as well as other elements like chromium, manganese, molybdenum, boron, and nickel for their various properties, including resistance to corrosion. Corrosion resistance is critical for constructions using steel, as it prevents deterioration caused by environmental conditions. While other metals like zinc might be used in a protective capacity, such as in galvanizing steel, it's nickel that is alloyed with the iron to create a more corrosion-resistant steel.