Concept:The earth's sphericity is proven by observable features like the horizon, ship visibility, and circumnavigation, not by rotation effects.Explanation:The circular horizon, ship's visibility, and circumnavigation of the earth are direct proofs that the earth is spherical.The deflection of winds is caused by the earth's rotation, not by its curved shape.Therefore, deflection of winds does not prove sphericity.Answer:B. Deflection of winds