What is the legal test for abuse of discretion when determining whether to reinstate probation or prison terms?

Courts have broad discretion to reinstate probation or impose a prison sentence, and whether to impose the upper term. We review a trial court's determination for abuse of discretion and would reverse only if there is a clear showing the sentence was arbitrary or irrational. (People v. Sandoval (2007) 41 Cal.4th 825, 847.) A trial court abuses its discretion "if it relies upon circumstances that are not relevant to the decision or that otherwise constitute an improper basis for decision. [Citations.]" (Ibid.)