Evidence is not to be adduced if, on objection by a client, the court finds that adducing the evidence would result in disclosure of—
(a) a confidential communication made between the client and a lawyer; or
(b) a confidential communication made between 2 or more lawyers acting for the client; or
(c) the contents of a confidential document (whether delivered or not) prepared by the client, lawyer or another person—
for the dominant purpose of the lawyer, or one or more of the lawyers, providing legal advice to the client.