The Most Accurate Statement with Regard to Treatment Research for Narcissistic

The most accurate statement with regard to treatment research for narcissistic personality disorder (Groopman & Cooper,2001) is that the research is

A) extremely limited in both number of studies and reports of successes.
B) extremely limited in number of studies, though some promising results have been reported.
C) extensive, though few positive results are reported.
D) extensive, though the studies are not scientific.