Concept:
The expansion of the informal sector in many developing countries is often associated with outsourcing, subcontracting and contractual employment.
Firms reduce production costs by transferring employment risks and labour obligations to workers employed outside the formal sector.
Step 1: Examine Assertion (A).
Many firms shift production activities to informal workers in order to:
• Reduce labour costs.
• Avoid long-term employment obligations.
• Minimize social security expenses.
• Increase flexibility.
Therefore,
\[
\boxed{\text{Assertion (A) is Correct.}}
\]
Step 2: Examine Reason (R).
Outsourcing and subcontracting often enable firms to avoid several labour regulations and transfer employment insecurity to workers employed on temporary or informal contracts.
Thus,
\[
\boxed{\text{Reason (R) is Correct.}}
\]
Step 3: Determine whether (R) explains (A).
The outsourcing of production is one of the major reasons behind the expansion of the informal sector.
Hence,
\[
\boxed{
\text{Reason (R) correctly explains Assertion (A).}
}
\]
Therefore,
\[
\boxed{\text{Correct Answer}=(A)}
\]