Collectively, Genetic Studies Have Found That Schizophrenia Was Associated with Literally

Collectively, genetic studies have found that schizophrenia was associated with literally thousands of gene variations, both common and rare. Which of the following is NOT one of the conclusions that was reached based on these studies?

A) Taken individually, none of the gene variants is capable of causing schizophrenia.
B) Even in combination, the genetic variants are only associated with an increased risk of developing schizophrenia.
C) No specific pattern of genetic variation can be identified as the cause of schizophrenia.
D) Genes associated with a particular chromosome location have been linked directly to the development of schizophrenia.