The correct answer is option 2, Geetanjali Shree. In this question, we are asked to identify the author of the book "Tomb of Sand". Let`s examine each option to understand why option 2 is the correct answer.

Option 1, Arundhati Roy, is a renowned Indian author, but she is not the author of the book "Tomb of Sand". She is known for her novel "The God of Small Things" and her work as a political activist.

Option 3, Chetan Bhagat, is a popular Indian author, but he is not the author of the book "Tomb of Sand". He is known for his novels like "Five Point Someone" and "2 States".

Option 4, Jhumpa Lahiri, is an acclaimed author, but she is not the author of the book "Tomb of Sand". She is known for her works like "Interpreter of Maladies" and "The Namesake".

Therefore, the correct answer is option 2, Geetanjali Shree. She is the author of the book "Tomb of Sand".