History can be a very scoring subject for UPSC if you are able to memorize well. Since it is so scoring and easy to study for anyone with a good memory, it is one of the most popular optional subjects in UPSC exams. Understanding the pros and cons of History optional is essential before putting it down as your option in the application form. It has synergy with General Studies. 50 marks question from modern India get covered in optional history. It is also useful in writing essays.