The correct answer is option 2, Cellulose. Rayon is a synthetic fiber that is made from natural cellulose, which is found in plants. Cellulose is extracted from wood pulp or cotton fibers and treated with chemicals to transform it into a semi-synthetic material called viscose. This viscose is then used as the raw material for manufacturing Rayon. Nylon, option 1, is a different type of synthetic fiber that is made from petroleum-based chemicals. Silicon, option 3, is a chemical element that is not used in the production of Rayon. Radium and Argon, option 4, are radioactive and inert gases respectively, which are also not relevant to the manufacturing process of Rayon.