Glucose and oxygen are required by the brain for a constant supply of energy to control the functions of our body organs. What will be the consequences if the brain is deprived of oxygen and glucose?
$I.$ Brain deprived of oxygen for just $5$ minutes will get permanently damaged.
$II.$ Glucose is important in the nerve impulse conduction.
$III.$ One side of the brain is unable to know what the other side is doing when it is deprived of oxygen.
$IV.$ Mental confusion will result if the brain is deprived of glucose.

• A
  $I$ and $II$
• B
  $III$ and $IV$
• C
  $I$ and $IV$
• D
  $II$ and $IV$