Characteristics. Both Ahab and Ishmael are fascinated by the whale, but whereas Ahab perceives him exclusively as evil, Ishmael keeps an open mind. Ahab has a static world view, blind to new information, but Ishmael's world view is constantly in flux as new insights and realizations occur.
It is less vivid; "raced after" emits a feeling of either action, suspense, or energy. It allows the reader to connect and fully understand what is going on. "ran after" is vague and emits little high energy.
Sorry for such late an answer, but I believe its A) Predicate Nominative.
