Explanation:

- Different types of unions cater to various employment sectors and skills.

- Option 1: Industrial union - Represents workers in a specific industry, regardless of the particular trade or skill.

- Option 2: General union - Correct. A general union covers employees from multiple industries, trades, and crafts, offering widespread representation.

- Option 3: Craft union - Focuses specifically on workers of a particular craft or trade, not across multiple sectors.

- Option 4: Region-cum-industry level union - Represents workers within a certain geographical area and industry, not as broad as a general union.