The correct answer is option 3, which includes occupations 1, 2, and 3 only.

1. Manufacturing: This refers to the production of goods through various processes, such as assembling, processing, and fabricating raw materials. Examples include automobile manufacturing, electronics production, and textile manufacturing.

2. Construction: This involves the building, repairing, and renovating of structures such as residential houses, commercial buildings, roads, bridges, and dams.

3. Gas and water supply: This includes the production, extraction, and distribution of natural gas and water to households, industries, and other consumers. It involves activities such as drilling, purifying, and supplying these resources.

4. Mining and quarrying: This option is not included in the secondary sector. Mining and quarrying involve the extraction of minerals, ores, and stones from the earth`s crust. These activities fall into the primary sector of the economy.

Therefore, occupations included in the secondary sector as per the national income accounts are manufacturing, construction, and gas and water supply.