Schizophrenia is a complex disorder and the symptoms are quite dramatic and not easily understood. There are factors that lead to onset of schizophrenia
• Biological
• Psychological
• Social and environmental factors.
Hence the option b is not correct.
In a study it is clearly explained that this disorder is not developed because of poor or bad parenting.
Hence the options c and d are not correct.
Genetics play a key role in the development of schizophrenia. This disorder usually runs in the families. Genetically the risk of developing a disorder is 15% if one parent has that disorder and 50% if both the parents have that disorder.
The rates of concordance that both twins having this disorder are higher among identical twins that is 60 to 84% compared to the fraternal twins.
Hence the correct option is.