Consider the following four compounds $I, II, III,$ and $IV$.
Choose the correct statement$(s)$.
$(A)$ The order of basicity is $II > I > III > IV$.
$(B)$ The magnitude of $pK_b$ difference between $I$ and $II$ is more than that between $III$ and $IV$.
$(C)$ Resonance effect is more in $III$ than in $IV$.
$(D)$ Steric effect makes compound $IV$ more basic than $III$.

• A
  $A, B$
• B
  $A, C$
• C
  $A, D$
• D
  $C, D$