答案及解析：[单选题]In the（），businesses offer services for which they charge a fee that is based on the number of size

问题：

[单选题] In the（），businesses offer services for which they charge a fee that is based on the number of size of transactions they process.Some of these services lend themselves well to operating on the Web.
A.Fee-for-Transaction Revenue Model
B.Advertising-Supported Revenue Models
C.Web Catalogue Revenue Models
D.Value chain