Correct Option
The correct option is Government-owned steel plants.
Explanation
Industries are classified on the basis of ownership into four distinct categories: Public Sector, Private Sector, Joint Sector, and Cooperative Sector. Public Sector industries are owned, operated, and maintained by the government (Central or State) to ensure social welfare and economic development.
Option Analysis
- Government-owned steel plants: Correct. Government-owned steel plants, such as the Steel Authority of India Limited (SAIL) or Bhilai Steel Plant, are owned and managed by the government. Therefore, they fall strictly under the Public Sector.
- Privately owned engineering firms: Incorrect. Privately owned engineering firms are owned and operated by individuals or a group of individuals. These fall under the Private Sector (e.g., Tata Motors).
- Joint ventures with foreign companies: Incorrect. Joint ventures involve a partnership between the state and private individuals or companies. While the government has a stake, these are classified as the Joint Sector (e.g., Maruti Udyog Ltd. in its initial phase), distinct from the purely Public Sector.
- Religious trust-owned enterprises: Incorrect. Enterprises owned by religious trusts or private organizations operate privately, often for specific causes or profit, and are classified under the Private Sector.
Key Takeaway
Public Sector industries are defined by government ownership and control, exemplified by major Public Sector Undertakings (PSUs) like SAIL (Steel) and BHEL (Heavy Electricals).