Select the most appropriate option that can substitute the highlighted segment in the given sentence. If there is no need to substitute it, select 'No substitution'.
We all should help each other.

Correct option is B

Option (b) is the correct substitution of the highlighted word.
· 'One another' is more formal, and is used less in comparison.
· Each other is more applicable when talking about only two people (or things).
· Using 'one another' is more relevant when there are more than two people (or things).