What is the mean of the column " A " in this DataFrame generated below? (choose the closest value) (you may need to import additional packages to run the below code!) import numpy as np rng=np. random. default rng(768561456987365) \#create a dataframe using those random values! df= pd.DataFrame ( rng. integers (0,100, size =(15,4)), columns=list ( ' ABCD)) 60.93 50.33 58.13 44.07