Concept: This question asks for matching important international legal instruments and conferences with their years.
Step 1: Match UN Charter.
The United Nations Charter came into force in 1945. It is the founding document of the United Nations.
\[
A \rightarrow IV
\]
Step 2: Match Covenant on Civil and Political Rights.
The International Covenant on Civil and Political Rights was adopted in 1966.
\[
B \rightarrow I
\]
Step 3: Match Stockholm Conference on Human Environment.
The Stockholm Conference on Human Environment was held in 1972. It was a landmark event in international environmental law.
\[
C \rightarrow II
\]
Step 4: Match Universal Declaration of Human Rights.
The Universal Declaration of Human Rights was adopted in 1948.
\[
D \rightarrow III
\]
Therefore, the correct matching is:
\[
A-IV,\ B-I,\ C-II,\ D-III
\]