What are the two unit factors that relate meters and millimeters? 

(a) 1000 mm/1 m and 1 m/1000 mm 

(b) 1000 mm/1 m and 1000 m/1 mm 

(c) 1 mm/1000 m and 1 m/1000 mm 

(d) 1 mm/1000 m and 1000 m/1 mm 

(e) None of the above.