Which one of the following alignments is obtained by development accompanied by tunneling?

Explanation:

The alignment obtained by development accompanied by tunneling is typically the "Mountain alignment."

Mountain alignment:

• When a railway or road needs to traverse through mountainous or hilly terrain, tunnels are often constructed to create a mountain alignment.
• This alignment involves tunneling through the mountains to maintain a relatively straight and efficient path.

 Additional InformationValley alignment:

• This alignment follows the natural contours of valleys and does not usually involve tunneling.

Cross country alignment:

• This alignment involves going straight across relatively flat or gently rolling terrain without following specific natural features.
• It also doesn't typically require tunneling.

Zig-zag alignment:

• Zig-zag alignment is used in mountainous regions as well, but it involves a series of switchbacks or sharp turns to gain elevation gradually while reducing the steepness of the ascent.
• Tunneling may still be required, but the primary feature of zig-zag alignment is the use of switchbacks rather than a direct tunnel.