Answer: Option (b) is the correct answer.
Step-by-step explanation:
Since, all the given distances are present in different units. So, convert them into same unit.
As there are 1000 meter present in 1 kilometer so, we convert all of them into meter as follows.

= 7 m
There are 0.01 m present in 1 cm.
So,
= 0.002 m
There are 0.001 m present in 1 mm.
So,
= 0.03 m
= 0.58 m
Thus, we can conclude that out of the given options shortest distance is 0.2 cm.