Thank you for your response.
the client does not want a separate internet as the 2 buildings is in the same compound. To run a hard line between buildings is not recommended as it will cost to much to cut a trench and i am also looking at the distance (500ft). i am thinking more of a wireless solution.
i should have mention, that building B needs to be on a network as the accounts departments is in there. Therefore my main problem is getting the internet in that building without running a hard line.