Answer the following question given this paragraph: Not long after Wegener's death, scientists recognized that there is convection in the mantle. Deeper material is hotter and so it rises. Near the surface, it becomes cooler and denser so it sinks. This creates a convection cell in the mantle. Q: How does deeper material cause convection in the mantle? Choices: - remains stable - folds - sinks then rises - rises then sinks A:
rises then sinks