Hi Dr Asad You have opted psychology as your optional. Well, if you want to get very good marks in psychology, you can achieve but you have to prepare this subject from more than one book. I mean to say that there is no one book available that can cover the whole of the syllabi of the subject.
However, you may try the followings:
1. Psychology by Robert Baron OR
2. Exploring psychology by David Myers OR
3. Psychology and life by Zimbardo OR
4. Psychology by Gerow OR
5. Understanding Psychology by Feldman OR
6. Psychology by Wyne Weiten
U may consult any one of the above mentioned texts. In addition, the following books may help you as well:
1. History of Psychology by Schulze OR by Hergenhahn
2. Abnormal Psychology by Comer OR by Neale & Davison
Best of Luck!
Regards.

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