Candidates can indeed choose subjects from their graduation as optional papers in the UPSC exam, provided those subjects are aligned with the UPSC's prescribed list. This choice allows candidates to leverage their existing knowledge and academic strength in their preparation. However, it is essential to ensure that the selected subjects have a comprehensive syllabus and sufficient resources available for effective study. This strategy can significantly enhance confidence and performance, as familiarity with the chosen subjects may facilitate a deeper understanding of complex concepts vital for the examination.