What is the test for responding to a jury's request for clarification?

"To perform their job properly and fairly, jurors must understand the legal principles they are charged with applying. It is the trial judge's function to facilitate such an understanding by any available means. . . . A jury's request for reinstruction or clarification should alert the trial judge that the jury has focused on what it believes are the critical issues in the case. The judge must give these inquires serious consideration." (People v. Thompkins (1987) 195 Cal.App.3d 244, 250.) The court must answer the jury's question and respond "in as simple and direct a manner as possible." (Id. at p. 253.)