What is confidentiality within the context of the practitioner-client relationship?

What is confidentiality within the context of the practitioner-client relationship?
 
  A) Assurance that the content of the sessions will be shared only on a need-to-know basis.
  B) Assurance that the practitioner is confident in his/her ability to aid the client.
  C) Assurance that the client's information will be kept confidential, secure, and not shared with others unless she/he signs a consent form.
  D) Assurance that the relationship will remain confidential and that the practitioner has the ability to build rapport with the client.