The correct answer is option 1: Christophe Jaffrelot.
Option 1: Christophe Jaffrelot is the author of the book "Pakistan Paradox: Instability and Resilience". He is a French political scientist and has extensively studied South Asia, particularly Pakistan and India. His book analyzes the complex dynamics of Pakistan, focusing on the paradoxical nature of the country`s political stability and resilience despite its frequent instances of instability.
Option 2: G Parthasarthy is not the author of the book "Pakistan Paradox: Instability and Resilience". He is a former Indian High Commissioner to Pakistan and has served in various diplomatic roles, but he is not the author of this particular book.
Option 3: Imran Khan is not the author of the book "Pakistan Paradox: Instability and Resilience". Imran Khan is the current Prime Minister of Pakistan, but he has not written this book.
Option 4: Mamnoon Hussain is not the author of the book "Pakistan Paradox: Instability and Resilience". Mamnoon Hussain was the 12th President of Pakistan, but he is not the author of this book.
In conclusion, the correct answer is option 1: Christophe