Which landform indicates a divergent continent-to-continent boundary?

• A. Mountain range
• B. Volcanic island arc
• C. Rift valley
• D. Plateau

Answer: (C)

A rift valley is indicative of a divergent continent-to-continent boundary. At these boundaries, tectonic plates move away from each other, leading to the formation of a rift as the land stretches and thins. The rift valley is characterized by a deep, elongated depression, which results from the tectonic forces pulling the crust apart. This process can eventually lead to the creation of new oceanic crust if the rifting continues enough, ultimately forming a new ocean basin over geological time.

In contrast, the other landforms mentioned do not represent the same tectonic processes. A mountain range typically forms at convergent boundaries where two plates collide. A volcanic island arc occurs at oceanic-oceanic divergent or convergent boundaries, where one oceanic plate is subducted under another, leading to volcanic activity. A plateau represents a flat elevated area, which can form through various processes but is not specifically associated with the divergent movement of continental plates. Therefore, the rift valley is the correct representation of a divergent continent-to-continent boundary.