Answer: A user authentication
A Peer-to-peer network architecture would work best for Edward and Matthew.
Although they have the option of creating a Client-Server type of network architecture, the number of people that they are currently working with would cost them a lot more than a peer-to-peer architecture.
One of the advantages of using a Peer-to-peer network architecture for a small network would be the access of files between all computers in the network. Even if one of the computers will fail, the other computers will still have access to the different files and information they will need to keep the company moving forward.
Software, unless you planned on permanently downloading the Music Album or Song to your computer's Hard Drive. i.e, you would use whatever Music or Media player you have installed on your computer, and that simply counts as Software.
Keyboard would be the correct answer