Identify the reaction in which diborane is produced on industrial scale?

• A

  Reaction of $\mathrm{BF}_3$ with $\mathrm{LiA} / \mathrm{H}_4$ in diethyl ether
• B

  Oxidation of $\mathrm{NaBH}_4$ with $\mathrm{I}_2$
• Correct answer
  C

  Reaction of $\mathrm{BF}_3$ with NaH at 450 K
• D

  By heating $\mathrm{H}_3 \mathrm{BO}_3$ to above 370 K temperature

Hence, the correct answer is option: 'C'.