Which Festivus tradition do these Gentoo penguins appear to be participating in?

A Feats of strength
B Festivus caroling
C Airing of grievances

It appears that our penguin friend is airing some grievances into the Antarctic air. This tradition of Festivus is a way to tell other celebrants how they’ve disappointed you in the past year. And Gentoos are no strangers to having similar ‘discussions.’

The correct answer is Airing of grievances.