Which of the following is NOT used in the manufacturing of stainless steel?

Sulfur

The correct is option 2. Sulphur.

The element that is NOT used in the manufacturing of stainless steel is Sulfur.

Stainless steel is primarily composed of iron, with chromium being the key alloying element that imparts its corrosion-resistant properties. Nickel is also commonly added to stainless steel to improve its strength and corrosion resistance. Carbon is used to control the hardness and strength of stainless steel through the process of carbonization. However, sulfur is typically not intentionally added to stainless steel because it can lead to brittleness and poor weldability. Therefore, option 2, sulfur, is the correct answer.