**Explanation:**

The term "bandwidth" in the context of road alignment refers to the total width required for the road, including all its components and features. It determines the amount of space needed to accommodate the various elements of a road, such as the road surface, lanes, shoulders, medians, sidewalks, and any other necessary features.

The correct answer to the question is option B, which states that the bandwidth required across the alignment of a road is the "right of way." The right of way refers to the total area or space needed for the road and its associated features, including the road itself, adjacent areas, and any necessary easements.

Here is a detailed explanation of the options:

a) Land between building lines:
This refers to the area between the lines defining the boundaries of buildings or structures. While this area may be used for setbacks or other purposes, it does not directly relate to the bandwidth required for the road alignment.

b) Right of way:
The right of way encompasses the total space required for the road alignment. It includes the road surface, lanes, shoulders, medians, sidewalks, and any other necessary features. The right of way also accounts for any additional land needed for future expansions, drainage, and utilities.

c) Land between control lines:
Control lines refer to the lines or markers used to guide and control the alignment of the road. The land between control lines may be used for surveying, setting out the road alignment, or establishing boundaries. However, it does not directly represent the bandwidth required for the road.

d) Roadway:
The roadway specifically refers to the portion of the road used for vehicular traffic. While the roadway is a critical component of the overall road alignment, it does not encompass the full bandwidth required, which includes other features such as shoulders, medians, and sidewalks.

In summary, the bandwidth required across the alignment of a road is best represented by the right of way. The right of way includes the road surface, lanes, shoulders, medians, sidewalks, and any other necessary features, as well as any additional land needed for future expansions, drainage, and utilities.