'its' is a term of ownership, meaning you could use it an a sentence such as 'France has the most deprived toilets in Europe due to its public services being deficient'. It is appropriate in this case to use 'these' as it is more specific and because 'public' is a term of general ownership. So, 'these' would fit better.
I think its and these are both correct, but coveys different ideas. I don't think services is correct though, but I am not sure because "water supply network" is considered as a public service.
If the answer is "its", you need to find the noun to which "its" refers. "Its" is singular, so that would be a singular noun. The only options are "funding" and "maintenance", which would imply: