Concept:Percentage of water in soil = mass of fresh soil samplemass of water lost×100.Explanation:Mass of empty crucible = 10 g.Mass of crucible + fresh soil = 20 g, so fresh soil = 20−10=10 g.Mass of crucible + dry soil = 16 g, so dry soil = 16−10=6 g.Mass of water lost = 10−6=4 g.Percentage of water = 104×100=40%.Answer:40% (Option C)