Assertion: The proportion of workers in agricultural sector in India has shown a decline over the last few decades.

Reasoning: The participation rate in secondary and tertiary sector has registered an increase in these two decades.

Both Assertion (A) and reasoning (R) are correct and R is the correct explanation of A.

The correct answer is Option 1: Both Assertion (A) and reasoning (R) are correct and R is the correct explanation of A. 

Assertion: The proportion of workers in agricultural sector in India has shown a decline over the last few decades. This statement is correct because over time, fewer people have remained dependent on agriculture as employment opportunities in other sectors increased.

Reasoning: The participation rate in secondary and tertiary sector has registered an increase in these two decades. This statement is also correct because industrial and service sectors have expanded, attracting more workers.

Why Reason (R) correctly explains Assertion (A): The increase in employment opportunities in the secondary and tertiary sectors caused workers to shift away from agriculture. As a result, the proportion of workers in the agricultural sector declined. Therefore, the Reason directly explains the Assertion.

NCERT: It is important to note that the proportion of workers in agricultural sector in India has shown a decline over the last few decades (58.2% in 2001 to 54.6% in 2011). Consequently, the participation rate in secondary and tertiary sector has registered an increase. This indicates a shift of dependence of workers from farm based occupations to non-farm based ones, indicating a sectoral shift in the economy of the country.