You forgot the options!
but let's assume that these could be the options, as posted before
A. stone's throw
Bmen's plans
Cit's place
Dwomen's plans
maybe it will help if i discuss those: A, C, and D are not plural possessive: for this the noun has to be in plural.
In contrast, B: "men" is a plural noun. This is also the correct option. So for a plural possessive, the noun itself needs to be in plural.
hope this helped! if you want, comment with your options and i will comment back.