Please read the codes below. Which variable is a Pandas DataFrame?

Line$1$: import pandas as pd

Line$2$: df$\_$raw$=$pd$.$read$\_$csv$(\text{'}$appevent$.$csv$\text{'},$encoding$=$"ISO$-8859-1",$skiprows$=1)$

Line$3$: for col in df$\_$raw.columns:

Line$4$: print$($col$)$

Line$5$: print$($df$\_$raw$[\text{'}$Source$\text{'}].$value$\_$counts$(),"$

$")$

Source

Value$\_$counts

col