Identify the correct statements with reference to landforms and plate-tectonics.

A. The violent volcanoes of South America are associated with ocean-continent convergence.

B. The Himalayas originated due to continent-continent convergence.

C. Hot spots are always located at plate boundaries.

D. Earth's persistent magnetic field is caused by the movement of molten metal in the inner core.

Choose the most appropriate answer from the options given below: