Statement (A): Each sp hybrid orbital has 50% s character

Statement (B): Each sp hybrid orbital has 50% p character

Statement (C): $\pi -\text{bond}$ is less reactive than $\sigma -$ bond

The sp hybrid orbital is formed by the inter mixing of  one pure s-orbital and 1 pure p-orbital.  So, the resultant sp orbital should have 50% s character and 50% p character.  Therefore, statement-I and II are correct.  As we know that the sigma bond was formed by the end on end inter nuclear axis of both the atomic orbitals.  Hence it is a strong bond.  Coming to pie bond it is formed by the lateral overlapping or sidewise overlapping of two pure p-orbitals or one p-orbital and one d-orbital or two pure d-orbitals.  So the pie bond the pie bond is a weak in strength than sigma bond.  Hence it is more reactive than sigma bond. Therefore statement-III is incorrect.