Answer
b. 140 hg
Work Step by Step
A weight of 140 kg is more than a typical person so this weight seems too big for a bicycle.
A weight of 140 g is less than 1 kg so this weight seems too small for a bicycle.
We know that 1 liter of water weighs 1 kg. A weight of 140 dag is equal to 1.4 kg so this weight seems too small for a bicycle, since this is the weight of just 1.4 liters of water.
A weight of 140 hg is equal to 14 kg. Since this is equal to the weight of 14 one-liter bottles of water, this seems like a reasonable weight for a bicycle.
The best estimate for the weight of a bicycle is 140 hg