Explanation:
as we know.
\(1 \,g =1000\, mg\)
Now, convert all option value in mg
\(16 \,g =16000\, mg\)
\(16.4\, g =16400\, mg\)
\(16.428\, g =16428\, mg\)
\(16.4284 \,g =16428.4\, mg\)
from above in 16428 all digits are significant and nearest to milligram.