The question refers to a reaction diagram (indicated by 'below mentioned reaction') which is not provided in the input text. Without the visual details of the reactants, reagents, and reaction conditions, it is impossible to identify the product 'X' or verify the correct option. Based on the tags (NEET 2020, Aldehydes & Ketones), this likely refers to a reaction such as the Rosenmund reduction, Stephen reaction, or Etard reaction, which are common topics in this chapter for that exam year.