What is the test for a judge's failure to strike a prior conviction?

A trial court's "failure to . . . strike a prior [felony] conviction allegation is subject to review under the deferential abuse of discretion standard." (People v. Carmony (2004) 33 Cal.4th 367, 374.) "[A] trial court will only abuse its discretion in failing to strike a prior felony conviction allegation in limited circumstances." (Id. at p. 378.) "In reviewing for abuse of discretion, we are guided by two fundamental precepts. First, ' "[t]he burden is on the party attacking the sentence to clearly show that the sentencing decision was irrational or arbitrary. [Citation.] In the absence of such a showing, the trial court is presumed to have acted to achieve the legitimate sentencing objectives, and its discretionary determination to impose a particular sentence will not be set aside on review." ' [Citations.] Second, a ' "decision will not be reversed merely because reasonable people might disagree. 'An appellate tribunal is neither authorized nor warranted in substituting its judgment for the judgment of the trial judge.' " ' [Citation.] Taken together, these precepts establish that a trial court does not abuse its discretion unless its decision is so irrational or arbitrary that no reasonable person could agree with it." (Id. at pp. 376-377.)