Concept:The metric system defines 1 metre = 100 centimetres = 1000 millimetres.Explanation:We know 1 m = 100 cm and 1 m = 1000 mm.Equating both: 1000 mm = 100 cm.Divide both sides by 1000: 1 mm = 100/1000 cm = 0.1 cm.Thus, one millimetre is equal to 0.1 centimetre.Answer:D. 0.1 cm