Which of the following statements about enzymes are true?
$i$. Enzymes lack nucleophilic groups.
$ii$. Enzymes are highly specific both in binding chiral substrates and in catalyzing their reactions.
$iii$. Enzymes catalyze chemical reactions by lowering the activation energy.
$iv$. Pepsin is a proteolytic enzyme.

• A
  $i$ and $iv$
• B
  $i$ and $iii$
• C
  $ii$,$iii$ and $iv$
• D
  $i$