Given $p$: $A$ man is a judge,$q$: $A$ man is honest. If $S_1$: If a man is a judge,then he is honest; $S_2$: If a man is a judge,then he is not honest; $S_3$: $A$ man is not a judge or he is honest; $S_4$: $A$ man is a judge and he is honest. Then:

• A
  $S_2 \equiv S_3$
• B
  $S_1 \equiv S_2$
• C
  $S_2 \equiv S_4$
• D
  $S_1 \equiv S_3$