Through which one of the following Straits, does a tunnel connect the United Kingdom and France?

The Channel Tunnel (Chunnel) is a fixed rail link between southern England and northern France that runs beneath the English Channel at its narrowest point, the Strait of Dover. The tunnel links Folkestone (Kent) in England with Coquelles (Pas-de-Calais) near Calais in France and its undersea section passes beneath the Strait of Dover, providing the only fixed link between Great Britain and continental Europe [2]. The pair of ports Dover (England) and Calais (France) face each other across the English Channel at this location, confirming the Strait of Dover as the crossing beneath which the tunnel was constructed [1]. Hence option 3 (Strait of Dover) is correct.

Sources

1. [2] https://www.gihub.org/connectivity-across-borders/case-studies/the-channel-tunnel/
2. [1] FUNDAMENTALS OF HUMAN GEOGRAPHY, CLASS XII (NCERT 2025 ed.) > Chapter 8: International Trade > Types of Port > p. 76