The correct answer is A. Phosphorus.
Phosphorus is a chemical element with the symbol P and atomic number 15. It is a non-metallic, pale yellow, odorless, tasteless, and highly flammable element. Phosphorus is the most reactive of all the non-metals and is the only non-metal that is naturally found in the form of a solid.
Phosphorus is used in the manufacture of safety matches because it is highly flammable. When phosphorus is struck against a rough surface, it ignites and produces a flame. This flame is then used to ignite the match head, which is made of a mixture of sulfur, potassium chlorate, and gum arabic.
The other options are incorrect because they are not as flammable as phosphorus. Magnesium is a silvery-white metal that is used in the manufacture of lightweight alloys. Silicon is a non-metallic, tetravalent metalloid that is used in the manufacture of semiconductors. Sulphur is a non-metallic, yellow element that is used in the manufacture of gunpowder and matches.