What is the test for a jury to decide whether to accept all, part or none of a witness's testimony?

The jury instructions made it clear to the jury that they were entitled to believe all, part, or none of a witness's testimony. In addition, the jury could decide whether or not to believe an expert's testimony. Respondent's cross-examination of appellant's witnesses put their testimony in question. Appellant's evidence cannot be described as undisputed or uncontradicted. On the contrary, it was hotly disputed, and the question of whether appellant was entitled to damages was a question of fact for the jury. (Gersick v. Shilling, supra, 97 Cal.App.2d 645.) Viewing the record in the light most favorable to the respondent, as we must, we find that the evidence supports the decision. (Ibid.)