Which of the following statements are correct?
$(I)$ $P_4$ molecule is very reactive because of angular strain.
$(II)$ The basicity of $H_3PO_3$ is $3$.
$(III)$ In gas phase,all $P-Cl$ bonds of $PCl_5$ have same bond length.
$(IV)$ In solid state,$PCl_5$ exists as an ionic solid,in which anion $[PCl_6]^-$ has octahedral and cation $[PCl_4]^+$ has tetrahedral shape.

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