The correct answer is D. H. G. Walls.
D. H. G. Walls is a British author who has written several books on self-help and personal development. His most famous book is “Zest for Life: How to Live a Happy and Fulfilling Life”. In this book, Walls shares his own personal experiences and insights on how to live a more fulfilling life. He discusses topics such as finding your purpose in life, overcoming obstacles, and living in the present moment.
Mark Twain is an American author who is best known for his novels “The Adventures of Tom Sawyer” and “The Adventures of Huckleberry Finn”. Emile Zola is a French author who is best known for his novels about the working class, such as “Germinal” and “L’Assommoir”. Virginia Woolf is an English author who is best known for her novels “Mrs. Dalloway” and “To the Lighthouse”.
All of these authors have written important and influential books, but none of them have written a book called “Zest for Life”. Therefore, the correct answer is D. H. G. Walls.