Identify the correct group of statements:
$I.$ Oxygen is carried by haemoglobin
$II.$ Oxygen is carried by carbonic anhydrase
$III.$ $CO_{2}$ is carried by haemoglobin
$IV.$ $SO_{2}$ is carried by haemoglobin
$V.$ Only oxygen is transported by the blood
$VI.$ Only $CO_{2}$ is transported by the blood
Choose the correct option.

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