The correct answer is: C. 10.21m
The formation width for a double line Broad Gauge track in cutting (excluding drains) as adopted on Indian Railways is 10.21m. This includes the width of the track itself, as well as the space required for ballast, drainage, and other infrastructure.
The width of the track itself is 1.676m. The ballast is a layer of crushed stone that supports the track and helps to distribute the weight of the train. The drainage system helps to remove water from the track bed, preventing it from becoming saturated and causing the track to settle. Other infrastructure, such as signals and switches, also takes up space.
The total width of the formation is therefore 10.21m. This is the minimum width required to safely accommodate a double line Broad Gauge track in a cutting.