The famous Hindi book "Kankal" was authored by which of the following writers?

Introduction / Context:
This question is from Indian literature and asks about the authorship of the Hindi work "Kankal". Jaishankar Prasad is an important figure in Hindi literature, and "Kankal" is one of his well known writings. Connecting such titles with their authors is a standard requirement in exams that test knowledge of Hindi literary heritage.

Given Data / Assumptions:

• The work mentioned is "Kankal".
• Four writers are listed as options, mixing modern and older authors.
• Only one of these writers is actually associated with "Kankal".
• The question is fact based and does not involve calculations.

Concept / Approach:
"Kankal" is a well known work by Jaishankar Prasad, who was a major Hindi poet, dramatist, and prose writer. He contributed significantly to the Chhayavad era of Hindi literature, and "Kankal" is counted among his important creations. The other options such as Ketan Bhagat, Mahesh Rao, and Nirmal Verma are contemporary authors associated with different books and styles. Therefore, linking "Kankal" with Jaishankar Prasad is the correct conceptual approach.

Step-by-Step Solution:
Step 1: Note that the question asks about the author of the Hindi work "Kankal". Step 2: Recall from Hindi literature that Jaishankar Prasad wrote several influential works, including "Kankal". Step 3: Recognise that the other listed authors belong to a more modern period and are not usually linked with this classic title. Step 4: Select Jaishankar Prasad as the correct option and eliminate the remaining names.

Verification / Alternative check:
Hindi literature textbooks, university syllabi, and exam guides all list "Kankal" under the works of Jaishankar Prasad. Bibliographies of his writing mention this title along with his plays, poems, and stories. Checking one or two reliable print or online references on Hindi literary history is enough to confirm the authorship of "Kankal".

Why Other Options Are Wrong:
Ketan Bhagat is a contemporary English language author and does not feature in lists of classic Hindi works such as "Kankal".
Mahesh Rao is known for modern novels and stories, not for this particular Hindi classic.
Nirmal Verma was an important Hindi writer, but "Kankal" is not counted among his works; it is associated with Jaishankar Prasad instead.

Common Pitfalls:
Students sometimes confuse names of Hindi authors because many of them are studied together, especially Prasad, Pant, Nirala, and Mahadevi Verma. Another pitfall is to guess a modern author simply because their name seems more familiar from current book markets. To avoid confusion, prepare a list of classic Hindi works and clearly pair each title with its correct author, revising this list often.

Final Answer:
The book "Kankal" was authored by Jaishankar Prasad, which is the correct answer.