Concept:
Governments of Less Developed Countries (LDCs) play an essential role in promoting economic development. Due to the presence of market failures, inadequate infrastructure, poverty, unemployment, and low levels of investment, governments are expected to actively intervene through planning, public investment, welfare programmes, and policy measures.
However, LDC governments are generally burdened with numerous socio-economic challenges such as:
• High public debt and fiscal deficits,
• Widespread poverty,
• Rapid population growth,
• Unemployment and underemployment,
• Inadequate infrastructure and low capital formation.
Step 1: Evaluate Assertion (A).
The assertion states that governments of LDCs must assume an active responsibility for the future well-being of their countries.
This statement is correct because government intervention is necessary to promote balanced economic growth, reduce poverty, improve infrastructure, and ensure social welfare.
\[
\boxed{\text{Assertion (A) is Correct}}
\]
Step 2: Evaluate Reason (R).
The reason states that governments of LDCs are not preoccupied with problems such as debts, deficits, poverty, population explosion, and unemployment.
This statement is incorrect. In reality, governments of LDCs are highly concerned with and actively deal with these challenges.
\[
\boxed{\text{Reason (R) is Incorrect}}
\]
Therefore,
\[
\boxed{\text{(A) is correct but (R) is not correct}}
\]
Hence, the correct option is
\[
\boxed{\text{(C)}}
\]