A 74-year-old man presents to the emergency room complaining of shortness of breath. He has markedly reduced his ordinary activities because he is no longer able to perform them without losing his breath. He stopped going to Penn State football games because he is concerned about climbing stairs in the Beaver Stadium. Even simple things like taking a bath, wearing his clothes and cooking a meal make him distressful. However, he reports no symptoms at rest. He prefers to sit on his couch most of the time. What is his NYHA Functional Classification for heart failure?