@usman qureshi
in my opinion you should not change islamic history with psychology.
You got good marks and you can get more marks in islamic history with a little more effort.
Psychology will be a new subject for you and you need extra effort to cover the syllabus of psychology. You have already prepared islamic history and so go with it.
Wishing you best of luck

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Success is never achieved by the size of our brain but it is always achieved by the quality of our thoughts.