In the context of popular Indian English fiction, who is the author of the bestselling novel "Half Girlfriend"?

Introduction / Context:
This question tests basic knowledge of popular Indian English fiction. "Half Girlfriend" is a widely known commercial novel that has been adapted into a film and frequently appears in discussions of modern Indian bestsellers. Many general knowledge exams include such questions to see if candidates are aware of contemporary popular culture as well as classic literature.

Given Data / Assumptions:

• The title "Half Girlfriend" is given as a bestselling Indian English novel.
• Four possible authors are listed: Chetan Bhagat, Amish Tripathi, Ravinder Singh and Salman Rushdie.
• We assume that only one of these is the correct author of the book.

Concept / Approach:
The approach is simple recall. Chetan Bhagat is known for campus and relationship based novels aimed at a mass audience. His works include "Five Point Someone", "2 States", "Revolution 2020" and "Half Girlfriend". Amish Tripathi is associated with mythological fiction such as the Shiva trilogy. Ravinder Singh is known for romantic novels like "I Too Had a Love Story". Salman Rushdie is a Booker Prize winning literary novelist, not a mass market romance writer. Recognising the genre and style helps identify the correct author.

Step-by-Step Solution:
Step 1: Recall which author is most strongly connected with the title "Half Girlfriend". This novel tells the story of a boy from Bihar and his complicated relationship with a girl he calls his half girlfriend. Step 2: Chetan Bhagat is widely publicised as the author of "Half Girlfriend" and appears on the book cover and in all promotions for the book and its film adaptation. Step 3: Amish Tripathi writes mythological and historical fantasy novels, not this type of contemporary college romance. Step 4: Ravinder Singh also writes romantic fiction, but his well known titles are different and do not include "Half Girlfriend". Step 5: Salman Rushdie focuses on complex literary fiction and has no connection with this commercial romance novel. Step 6: Therefore, the only correct choice for the author of "Half Girlfriend" is Chetan Bhagat.

Verification / Alternative check:
Checking any bookstore listing or publisher description confirms that "Half Girlfriend" is by Chetan Bhagat. The movie adaptation credits the story to him as well. Online catalogues, library records and media interviews all consistently identify him as the author. None of these sources link the book with Amish Tripathi, Ravinder Singh or Salman Rushdie.

Why Other Options Are Wrong:

• Amish Tripathi is wrong because he is known for mythological series like "The Immortals of Meluha" rather than contemporary campus romances.
• Ravinder Singh is wrong because his famous works include "I Too Had a Love Story" and "Can Love Happen Twice?", not "Half Girlfriend".
• Salman Rushdie is wrong because his major works such as "Midnight's Children" and "The Satanic Verses" belong to a completely different literary category.

Common Pitfalls:
Candidates sometimes confuse Indian popular fiction authors because many of them write about relationships and college life. Another mistake is to guess based only on name recognition without considering the genre of the book. Remembering a few key titles associated with each major author helps avoid these errors.

Final Answer:
The novel "Half Girlfriend" is written by Chetan Bhagat.