What is the test for an abuse of discretion in sentencing decisions for probation?

We review a court's sentencing decisions, including granting or denying probation, for an abuse of discretion. The trial court possesses broad discretion to determine whether a defendant is eligible for probation. (People v. Olguin (2008) 45 Cal.4th 375, 379.) Section 1203 provides that, "Except in unusual cases where the interests of justice would best be served if the person is granted probation, probation shall not be granted to any of the following persons: [] . . . [] (4) Any person who has been previously convicted twice in this state of a felony or in any other place of a public offense which, if committed in this state, would have been punishable as a felony." ( 1203, subd. (e).)