During the 1970s and 1980s, NCVS and UCR statistics revealed opposite trends in crime. What conclusion did criminologists reach on this issue?

Group of answer choices:
- The increase in crime revealed by UCR statistics represented a real increase in crime.
- The upward trend in UCR crime is not a "real" increase, but instead reflected increases in police productivity.
- The decrease in NCVS crime rates revealed a greater reluctance among citizens to report victimizations to NCVS interviewers.