Lala Lajpat Rai / लाला लाजपत राय
General competitive examinations frequently test candidates on Current Affairs topics. Questions like "Who is the author of the book 'Unhappy India'? ‘अ..." are designed to verify factual recall and general awareness. Regular practice on similar MCQs ensures a higher accuracy rate. The correct option here is Lala Lajpat Rai / लाला लाजपत राय.