9-10Python panda

What is the missing function that changes instances of the string 'Missing' to the string 'Zero'? O str.update O replace O change changevals Question 10 5 pts What will get printed? people = { 'first': ['Corey', 'Jane', 'John', 'Chris', np.nan, None, 'NA'], 'last': ['Schafer', 'Doe', 'Doe', 'Schafer', np.nan, np.nan, 'Missing"], 'email': ['Corey@Schafer@gmail.com', 'JaneDoe@email.com', 'JohnDoe@email.com', None, np.nan, np.nan, 'Missing'], 'age': ['33', '55', '63','36', None, None, 'Missing"] df = pd.DataFrame(people) num_rows, num_cols = df.shape print(num_cols)