What is the test for asserting privilege in a witness testimony?

The principle that a witness may not be compelled to incriminate himself is a "bedrock principle" of American law embedded in the federal and state Constitutions. (People v. Seijas (2005) 36 Cal.4th 291, 304 (Seijas).) A witness may properly assert the privilege who has " 'reasonable cause to apprehend danger from a direct answer.' " (Ibid.) The privilege is liberally interpreted. A witness may not avoid testifying simply by stating that to do so would be incriminating. However, " '[t]o sustain the privilege, it need only be evident from the implications of the question, in the setting in which it is asked, that a responsive answer to the question or explanation of why it cannot be answered might be dangerous because injurious disclosure could result.' [Citation.]" (Ibid.) The assertion of the privilege must be allowed unless after a careful consideration of all the circumstances the answers sought "cannot possibly" have a tendency to incriminate. (Id. at pp. 304-305; see also Evid. Code, 404.)