Who is the author of the famous book titled "Unhappy India"?

Introduction / Context:
This question tests your knowledge of important books written during India's freedom struggle and the national movement. "Unhappy India" is a well known work that criticises British rule and responds to misrepresentations of India by foreign writers. Linking this title with the correct freedom fighter is essential for history and general knowledge based examinations.

Given Data / Assumptions:

• The book title mentioned is "Unhappy India".
• Four options are provided: three named authors and one generic "None of these" choice.
• The task is to identify which of the named individuals actually wrote this book.
• No dates or events need to be calculated; this is a static GK fact from modern Indian history.

Concept / Approach:
The concept tested is the association between national leaders of the freedom movement and their writings. "Unhappy India" was written by Lala Lajpat Rai as a strong reply to Katherine Mayo's book "Mother India". He used it to highlight distortions about Indian society and to defend India during the colonial period. By remembering this connection, you can quickly select the right author in the options.

Step-by-Step Solution:
Step 1: Focus on the title "Unhappy India" and place it mentally in the context of the Indian freedom struggle. Step 2: Recall which national leader is historically known for writing this reply to colonial criticism. Step 3: Remember that Lala Lajpat Rai wrote "Unhappy India" to counter negative portrayals of India. Step 4: Mark Lala Lajpat Rai as the correct answer and rule out the remaining options.

Verification / Alternative check:
You can confirm this using standard history textbooks, competitive exam guides on the Indian national movement, or dedicated lists of books by freedom fighters. All such references consistently identify Lala Lajpat Rai as the author of "Unhappy India". Cross checking with reliable online and print sources will always reproduce the same pairing of book and author. Since this is a permanent historical fact, learning it once with proper understanding is enough for long term recall.

Why Other Options Are Wrong:
Vikram Seth is a contemporary Indian novelist and poet known for books like "A Suitable Boy"; he did not write "Unhappy India".
Chetan Bhagat is a modern popular fiction writer whose works focus on youth and contemporary issues, not on colonial era polemics.
"None of these" is incorrect because one of the listed authors, Lala Lajpat Rai, is indeed the right answer.

Common Pitfalls:
Students sometimes confuse "Unhappy India" with other titles from the freedom struggle era, such as autobiographies or collections of speeches. Another common mistake is to select "None of these" when unsure, instead of recalling that Lala Lajpat Rai wrote an important reply to "Mother India". To avoid such confusion, create a clear mapping of major freedom fighters and their key books and revise it frequently.

Final Answer:
The author of the book "Unhappy India" is Lala Lajpat Rai, so that is the correct option.