Final answer:
The primary objective of truth-in-sentencing laws is to ensure that offenders serve most of the sentence imposed by courts, enhancing sentence predictability and the justice system's credibility.
Step-by-step explanation:
The primary objective of truth-in-sentencing laws is to ensure that convicted individuals serve a substantial proportion of the sentence imposed by the court before becoming eligible for release. Option 4, which mentions encouraging early release programs, is not the core purpose of truth-in-sentencing laws; rather, such laws often limit the possibility of early release. The aim of these laws is not to increase discretion in sentencing or to directly reduce prison overcrowding, but to provide a more transparent and predictable sentencing process, which can have a deterrent effect on would-be offenders by ensuring that the punishment will indeed be served as handed down by the judicial system. Furthermore, truth-in-sentencing laws serve to enhance the credibility of the criminal justice system by ensuring that sentencing reflects the severity of the crime committed.