52 kg rails are mostly used in A. Broad Gauge B. Meter Gauge C. Narrow Gauge D. Both (A) and (B)

The correct answer is: Both (A) and (B).

52 kg rails are mostly used in broad gauge and meter gauge railways. They are also used in some narrow gauge railways, but less commonly.

Broad gauge railways have a track gauge of 1,676 mm (5 ft 6 in). Meter gauge railways have a track gauge of 1,000 mm (3 ft 3 3⁄8 in). Narrow gauge railways have a track gauge of less than 1,000 mm.

52 kg rails are made of steel and are very strong. They are able to support heavy loads and are resistant to wear and tear. They are also relatively easy to install and maintain.

52 kg rails are used in a variety of applications, including:

• Passenger railways
• Freight railways
• Industrial railways
• Mine railways
• Tramways

They are also used in some military applications, such as tank railways.