Answer: The most obvious symbol in The Old Man and the Sea is C. the marlin.
Step-by-step explanation: The Old Man and the Sea is a novel written by Ernest Hemingway and published in 1952. Symbolism plays an important role in the novel. Moreover, the most obvious symbol is C. the marlin, which represents strength and courage. The marlin is Santiago's opponent but it is also the one that brings out the best of him. The marlin encourages Santiago to be braver. Furthermore, the marlin is male and old; in that sense, it also comes to symbolize the old man.