Per user based pricing models can be controversial for which reason?

Per user based pricing models can be controversial for which reason?

• A. Users are like 'subscribers' and are typically subject to pay whether or not they use the data
• B. There are generally no mechanisms to transfer a service from one user to another in most market data agreements should a user leave the firm or change jobs
• C. They do not account for scale (e.g. there is no discounting as user numbers grow)
• D. They require non-display usage to be billed separately

Answer: (A)