A non-profit organization decides to use an accounting software solution designed for non-profits. The solution is hosted on a commercial provider's site but the accounting information suchas the general ledger is stored at the non-profit organization's network. Access to the software application is done through an interface that uses a coneventional web browser. The solution is being used by many other non-profit. Which security structure is likely to be in place:

a) a firewall protecting the software at the provider

b) a VPN protecting access to non-profit site

c) a and b

d) a and b and the VPN protecting the access to the software provider site.