AI-generated practice question — model-generated for extra practice, not a previous-year CBSE board question.
Answer: (B)
Growth in agriculture and industry increased demand for support services, rising incomes created new service demands, and IT-based services expanded rapidly.
The textbook (Chapter 2) lists four specific reasons for the tertiary sector's rise: (1) need for basic government services, (2) development of agriculture/industry creating demand for transport, trade, storage, (3) rising incomes driving demand for services like tourism, private hospitals, and (4) rapid growth of IT/ICT-based services. Option B captures reasons 2, 3, and 4 accurately. Options A, C, and D are factually incorrect — all three sectors grew, the government did not deliberately reduce investment in primary/secondary, and secondary output did not fall.