Which code block is an example of the OOP interface for matplotlib? import matplotlib.pyplot as plt plt.plot([1, 2, 3], [5, 6, 7]) import matplotlib.pyplot as plt fig, ax = plt.subplots() plt.plot([1, 2, 3], [5, 6, 7]) import matplotlib.pyplot as plt fig, ax = plt.subplots() ax.plot([1, 2, 3], [5, 6, 7])