Concept:A syncline is a downward fold in rock layers, so it belongs to folding structures that create fold mountains.
Explanation:A syncline is a trough-like fold where the rock layers bend downward.
This shape is produced by compressional forces acting on the Earth's crust.
When two sides of the crust push toward each other, the layers bend rather than break.
The upward bends are called anticlines, while the downward bends are called synclines.
These paired folds form fold mountains over long periods of time.
Examples include the Himalayas and the Alps.
Block mountains are caused by faulting, not folding.
Volcanic mountains are built from erupted lava and ash.
Residual mountains are left behind after erosion wears down surrounding land.
Therefore, the mountain type directly associated with a syncline is the fold mountain.
Answer:B. fold mountain