Which novella is associated with Joseph Conrad?

The novella associated with Joseph Conrad is "Heart of Darkness." This work, published in 1899, explores themes of imperialism, colonialism, and the darkness within human nature through the journey of Marlow into the Congo River basin. Conrad's narrative technique, particularly his use of a frame story and complex characterizations, contributes to the depth of the novella. The text is often studied for its rich symbolic content and critique of European colonial practices.

The other options do not relate to Conrad: "The Importance of Being Earnest" is a play by Oscar Wilde, "The Jungle Book" is a collection of stories by Rudyard Kipling, and "Pygmalion" is a play by George Bernard Shaw. Each of these works is significant in its own right but distinctly separate from Conrad’s literary contributions.