In which way should a pilot confirm received light signals in flight?

Question

Question PPL(H) - Private Pilot License - Air Law

QuizVDS · Accepted Answer

Rock the wings (in the daytime)

QuizVDS · Answer

Apply some changes of RPM

QuizVDS · Answer

Apply some fast pitch changes

QuizVDS · Answer

Apply some changes of the rudder

Id 79 - PPL(H) EN - In which way should a pilot confirm received light signals in flight?