$112$ points

Which Pandas method below would you use to replace missing values in a column called pw in a DataFrame called df where the median value of the column was pw med.?

$\text{'}]=$ df$[\text{'}$pw$\text{'}].$fillna$($pw$\_$med$)$

df $=$ df $[\text{'}$NaN$\text{'}].$median$()$

$\text{'}$pw$\text{'}]=$ df$.$median$()$

$df=df*$ isnull$()$ any$()$