What is the greatest length xxx such that 3123\frac{1}{2}321 m and 8348\frac{3}{4}843 m are integral multiples of xxx ?A1121\frac{1}{2}121 mB1131\frac{1}{3}131 mC1141\frac{1}{4}141 mD1341\frac{3}{4}143 m