_______ is the practice of relying on the judgment of police leadership and rank-and-file officers to decide which laws to enforce. A. Community policing B. Selective enforcement C. Incident-based coercion D. Uniform compassion

The answer to this question is "B: selective enforcement." This happens on a number of different levels in law enforcement. If laws are still on the books, then in theory they are supposed to be enforced. But some laws are outdated, and police simply don't bother enforcing them anymore. Sometimes, this can be because their constitutionality is an issue. For example, despite Supreme Court rulings to the contrary, some states still have laws on the books that criminalize certain types of sexual behavior. These laws are not enforced because prosecutions under them would probably be overturned by courts. But many were not enforced in the first place, because police did not see the need to enforce them and because they could not feasibly be enforced. Another example is the selective enforcement of federal laws against marijuana. Many states have legalized the drug for either recreational or medicinal purposes, and the federal government has not generally taken action to enforce its own laws on this matter.
But by far the most common examples of selective enforcement are everyday decisions made by law enforcement officers. If I cross the street illegally to enter my place of work, I am guilty of jaywalking. But police do not generally enforce this law unless there is a danger posed by my doing so. Police may also decline to give a speeding ticket to a person who is close to home or who is only a few miles per hour over the limit. Of course, selective enforcement has a more problematic side as well. Many critics of criminal justice in this country have pointed out that enforcement tends to fall heaviest on less affluent communities and people of color, especially black people. The so-called "war on drugs," for example, resulted in the incarceration of millions of African American men on drug charges. At the same time, authorities may be lax in enforcing other laws that might affect other (typically white) communities that are more affluent, like insurance or securities fraud. In this sense, societies and those who police them choose which activities they will effectively criminalize through their enforcement.
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Also called “enforcement discretion,” this process whereby individuals in positions of power employ a degree of judgment as to what punishment to enforce is known as “selective enforcement” (answer B). When such judgment demonstrates bias, it is regarded as a corrupt practice and abuse of the law. In US government, the prosecutor is free to exercise this discretion in a judicial setting.
The most common example of selective enforcement is the case of police officers issuing traffic tickets. They may not issue tickets to everyone they pull over (their decision might depend on anything from the appearance of the person or their vehicle to their driving speed). When selective enforcement is employed, officers may issue warnings in order to deter behavior that is offensive. Doing so often reduces legal costs involved in full-scale judicial proceedings.