The correct answer to the question, "Who among the following is the author of the book `The Indian Struggle, 1920 - 1934`?" is option 3, Subhash Chandra Bose.

Option 1, Maulana Abul Kalam, is not the correct answer. It should be noted that Maulana Abul Kalam Azad is a renowned freedom fighter and scholar, but he is not the author of this particular book.

Option 2, Jayprakash Narayan, is also not the correct answer. Jayprakash Narayan, also known as JP, was a prominent Indian political leader and social reformer, but he did not author this book.

Option 4, Manabendra Nath Roy, is not the correct answer either. Manabendra Nath Roy was a philosopher and political leader, but he is not the author of `The Indian Struggle, 1920 - 1934`.

Therefore, the correct answer remains option 3, Subhash Chandra Bose. Subhash Chandra Bose was a key figure in the Indian Independence Movement and the leader of the Indian National Army. This book is a firsthand account of his experiences and the struggles faced by India during the period from 1920 to 1934