Question

read the following excerpt from levitt and dubners freakonomics.
a key fact of white - collar crime is that we hear about only the very slim fraction of people who are caught cheating. most embezzlers lead quiet and theoretically happy lives; employees who steal company property are rarely detected.
with street crime, meanwhile, that is not the case. a mugging or a burglary or a murder is usually tallied whether or not the criminal is caught. a street crime has a victim, who typically reports the crime to the police, who generate data, which in turn generate thousands of academic papers by criminologists, sociologists, and economists. but white - collar crime presents no obvious victim.
in this excerpt, the authors present
a comparison between various criminals
an argument in favor of reporting crime.
a contrast between different types of crime.
an argument against embezzlement.

Explanation:

The text first describes white - collar crime (low detection rate, no obvious victim) and then street crime (usually reported, has a victim). This is clearly showing the differences between two types of crime, which is a contrast.

Answer:

C. a contrast between different types of crime.