3-4Python panda

Question 3 What is the method to update/change the index in a dataframe after the dataframe has been created? O index_col() O alter_index() O update_index() O set_index() Question 4 4 pts What is the difference in indexes between df and df2? import pandas as pd df = pd.read_csv('survey_results_public.csv', index_col = 'Respondents') df2 = pd.read_csv("survey_results_public.csv") There is no difference: O df2's index will be the first column in survey_results_public.csv. af's index will be Respondents O df2's will not have an index. df's index is Respondents O df2's index is a non-named integer. df's index is Respondents