What Do the Findings of Various Research Studies into the Use

What do the findings of various research studies into the use of pornography indicate is the relationship between violent behaviour and viewing pornography?

A) Those who view more than 5 hours of pornography per week are much more likely to exhibit violent behaviour than others who view less or none.
B) There is no clear link between obscene material and antisocial or violent behaviour.
C) The link between violence and pornography viewing appears to pertain to young males, under the age of 25 only.
D) Convicted rapists report having viewed more pornography than the general population.