The Major Criticism of Lovaas's Research Findings on Autism Was

The major criticism of Lovaas's research findings on autism was that his research

A) was not a true experiment because participants were not randomly assigned to treatment and control groups.
B) used physical pain as an unethical form of punishment.
C) can never be replicated because the drugs he administered to the children are now illegal.
D) was sexist as he only studied males with autism.