What is the test for credibility of a witness?

"Although we must ensure the evidence is reasonable, credible, and of solid value, . . . it is the exclusive province of the trial judge or jury to determine the credibility of a witness and the truth or falsity of the facts on which that determination depends." (People v. Jones (1990) 51 Cal.3d 294, 314.) "Thus, if the verdict is supported by substantial evidence, we must accord due deference to the trier of fact and not substitute our evaluation of a witness's credibility for that of the fact finder." (Ibid.)

b. Analysis