Which one of the following statements regarding oxidation and reduction reactions is NOT correct?

Statement (a) is incorrect. According to the classical definition, if a substance LOSES hydrogen during a reaction, it is OXIDIZED, not reduced. Conversely, gaining hydrogen means reduction. The correct definitions are: Oxidation = gain of oxygen OR loss of hydrogen; Reduction = loss of oxygen OR gain of hydrogen. Statements (b), (c), and (d) correctly describe these definitions. In terms of electrons, oxidation is loss of electrons and reduction is gain of electrons (OIL RIG).