Stainless steel is usually made by alloying the steel with A. Copper and nickel B. Copper and chromium C. Chromium and nickel D. Manganese and copper

The correct answer is C. Chromium and

Stainless steel is an alloy of iron with a minimum of 10.5% chromium. The chromium forms a chromium oxide layer on the surface of the steel, which protects it from corrosion. Nickel is often added to stainless steel to improve its strength and toughness. Other elements that may be added to stainless steel include manganese, molybdenum, and silicon.

Copper is not typically added to stainless steel, as it can cause the steel to become brittle. Manganese is sometimes added to stainless steel to improve its strength, but it can also cause the steel to become more susceptible to corrosion. Silicon is sometimes added to stainless steel to improve its machinability, but it can also cause the steel to become more susceptible to corrosion.

Therefore, the correct answer is C. Chromium and nickel.