Telangana has been actively promoting industrial development through:

Special Economic Zones (SEZs)
Tax incentives
Infrastructure development
All of the above

The correct answer is D) All of the above.

Telangana has been actively promoting industrial development through a number of initiatives, including the establishment of Special Economic Zones (SEZs), the provision of tax incentives, and the development of infrastructure.

SEZs are designated areas that offer a number of benefits to businesses, including tax breaks, duty-free imports and exports, and simplified customs procedures. Telangana has established a number of SEZs, including the Hyderabad Pharma City, the Rajiv Gandhi International Airport SEZ, and the IT and ITeS SEZ.

The state also offers a number of tax incentives to businesses, including a 100% exemption on corporate tax for the first five years of operation, a 50% exemption for the next five years, and a 25% exemption for the following five years.

Telangana has also invested heavily in infrastructure development, including the construction of roads, bridges, and airports. The state has also developed a number of industrial parks, which provide businesses with access to land, water, power, and other infrastructure.

These initiatives have helped to make Telangana a popular destination for businesses, and the state has seen significant growth in industrial investment in recent years.