The correct answer is (a) Service sector.
The service sector is the largest and fastest-growing sector of the Indian economy, accounting for over 50% of GDP in 2020. The sector is driven by growth in the IT and ITeS, financial services, and tourism industries.
The agriculture sector is the second largest sector of the Indian economy, accounting for about 15% of GDP in 2020. The sector is labor-intensive and employs about 50% of the workforce.
The industrial sector is the third largest sector of the Indian economy, accounting for about 30% of GDP in 2020. The sector is capital-intensive and employs about 25% of the workforce.
The foreign trade sector is a small but growing sector of the Indian economy, accounting for about 5% of GDP in 2020. The sector is driven by growth in exports of goods and services.
In conclusion, the service sector is the largest and fastest-growing sector of the Indian economy, accounting for over 50% of GDP in 2020. The sector is driven by growth in the IT and ITeS, financial services, and tourism industries.