Concept:
Several important child protection and welfare laws were enacted in India in different years.
Step 1:
The Protection of Children from Sexual Offences (POCSO) Act was enacted in 2012.
\[
A \rightarrow IV
\]
Step 2:
The Right to Education (RTE) Act was enacted in 2009.
\[
B \rightarrow III
\]
Step 3:
The Commissions for Protection of Child Rights (CPCR) Act was enacted in 2005.
\[
C \rightarrow II
\]
Step 4:
The Juvenile Justice Amendment Act was passed in 2021.
\[
D \rightarrow I
\]
Step 5:
Thus, the correct arrangement is:
\[
A-IV,\ B-III,\ C-II,\ D-I
\]
\[
\boxed{\text{(4) A-IV, B-III, C-II, D-I}}
\]