Denture stability refers to resistance of a denture:: (A) To move in a vertical direction away from basal seat, (B) To move in a vertical dimension towards basal seat, (C) To movements on its tissue foundation especially to lateral forces, (D) Against any kind of movement more the 24 µm in any direction
Answer is C. Stability (GPT-9): 

That quality of maintaining a constant character or position in the presence of forces that threaten to disturb it; the quality of being stable; to stand or endure.
The quality of a complete or removable partial denture to be firm, steady, or constant, to resist displacement by functional horizontal or rotational stresses.
Resistance to horizontal displacement of a prosthesis.