Installing a network infrastructure

You have been hired by a small company to install network infrastructure with shared storage. The office has 15 users. The accounting department, which has one user, does not want to be on the same network as the operation network and does not want to share the storage with any other users.
Please consider the following Technology or some of it:
Windows Server and AD
DHCP
SubNet Mask
NAS
Print Server
Povide diagrams of at least two design options. Discuss and compare the advantages and disadvantages of each proposed design and justify your recommendations. Consider cost, security, on-going maintenance, adding new users, printing, log-in, and Internet connection to all users.