What was the name of the German defensive line that ran nearly 400 miles across Germany's western border, extending from the Netherlands southward to Switzerland

A. Siegfried line

B. Gothic like

C. Maginot line

D. Alpine line

It was the Siegfried Line, an extremely massive series of fortification that took 3 years and was done in stealth.

A. Siegfried line

Explanation:

The Siegfried Line or West Wall was a defense system during World War II over 630 kilometers, which consisted of more than 18,000 bunkers, tunnels and tank traps. It began at the height of the town of Cleveris, on the southern border with Holland, and ended at the height of Weil am Rhein on the border with Switzerland. The original objective of the line was propagandistic. In this way, the Germans saw the Siegfried Line as an assertion that Germany's foreign policy was defensive, and that they felt safe in the face of an imminent French invasion, as the Germans claimed.