The answer is: C. 0.00427 m.
A) 1 km = 1000000 mm.
d = 0.0000427 km · 1000000 mm/km.
d = 47.7 mm.
B) 1 hm = 100000 mm.
d = 0.000427 hm · 100000 mm/hm.
d = 42.7 mm.
C) 1 m = 1000 mm.
d = 0.00427 m · 1000 mm/m.
d = 4.27 mm.
D) 1 cm = 10 mm.
d = 4.27 cm · 10 mm/cm.
d = 42.7 mm.
Millimeter (abbreviated: mm, a thousandth part of metar) is an unit of distance in the metric system.