One of the Drawbacks of Using Cloud Computing and SaaS

One of the drawbacks of using cloud computing and SaaS is that ________.

A) these services require significant technical knowledge
B) these services are generally very expensive to access
C) these services can sometimes be unreliable and may not function when you need them to
D) these services might share, distribute, mine, or expose data that you wish to have kept private
E) these services tie you to one particular platform