Which Statement Qualifies as a Hypothesis

Which statement qualifies as a hypothesis?

A) Children whose parents argue in their presence are more likely than other children to try illegal drugs.
B) Which parental behaviours are associated with an increased likelihood of teenage illegal drug use?
C) What are the differences between children whose parents argue in their presence and those whose parents do not argue in their presence?
D) There are many differences between children whose parents argue in their presence and those whose parents do not argue in their presence.