In a well-controlled, randomly assigned study, researchers compared two groups of people: one group was on a waitlist for therapy, and the other received 6 weeks of xyz therapy. Results showed that both groups had less anxiety after 6 weeks, and the xyz therapy grouphad significantly fewer symptoms than the waitlist group.
What is the strongest claim that can be made here?
a. Xyz therapy is correlated with improved anxiety for this group.
b. Xyz therapy might be effective in treating anxiety.
c. Xyz therapy decreased anxiety for this group.
d. Xyz therapy is probably not worth it because anxiety gets better with time.