Which freedom fighter wrote the book titled "An Introduction of the Dreamland"?

Introduction / Context:
This question comes from the literature of India's freedom struggle and focuses on lesser known writings of revolutionaries. "An Introduction of the Dreamland" is connected with the revolutionary ideas and aspirations of young nationalists. Identifying the correct author helps you appreciate that the freedom movement was not only fought on the streets but also through thoughtful writings.

Given Data / Assumptions:

• The book title is "An Introduction of the Dreamland".
• Four famous freedom fighters are listed as possible authors.
• Only one of them is associated with this particular work.
• The question is based on static history and does not require mathematical calculations.

Concept / Approach:
Bhagat Singh, besides being a revolutionary, was also a serious thinker and writer who produced essays and articles on revolution and society. "An Introduction of the Dreamland" is attributed to him as part of his intellectual contribution to the freedom struggle. Other leaders such as Tilak, Savarkar, and Subhas Chandra Bose also wrote important works, but they are associated with different titles. Therefore, by connecting this book with Bhagat Singh, you can choose the correct answer.

Step-by-Step Solution:
Step 1: Observe that the question is asking which freedom fighter wrote "An Introduction of the Dreamland". Step 2: Recall that Bhagat Singh was not only a revolutionary activist but also an author of essays and ideological pieces. Step 3: Match the title "An Introduction of the Dreamland" with Bhagat Singh based on history and exam preparation material. Step 4: Mark Bhagat Singh as the correct option and eliminate the other three names.

Verification / Alternative check:
You can verify this by consulting compilations of Bhagat Singh's writings and scholarly works on Indian revolutionary literature. Some competitive exam books on freedom fighters list this title under his name, highlighting the intellectual side of his contribution. Cross checking with more than one reliable reference ensures that you remember this pairing correctly for future exams.

Why Other Options Are Wrong:
Bal Gangadhar Tilak wrote famous works such as "Gita Rahasya", not "An Introduction of the Dreamland".
Vinayak Damodar Savarkar authored books like "The Indian War of Independence 1857" and various writings on Hindutva, not this title.
Subhas Chandra Bose is known for works like "The Indian Struggle", which again is a different book from the one in the question.

Common Pitfalls:
Students often confuse writings of different freedom fighters because many of them have titles related to struggle, revolution, or dreams of a free India. Another pitfall is to guess one of the more widely known leaders such as Tilak or Bose without recalling the correct book title. To avoid such errors, prepare a table linking major freedom fighters with their specific books and essays and revise it regularly.

Final Answer:
The book "An Introduction of the Dreamland" was written by Bhagat Singh, so that is the correct answer.