How can a pilot confirm a search and rescue signal on ground in flight?

Question

Question Quiz SPL - Sailplane Pilot License - Air Law

QuizVDS · Accepted Answer

Rock the wings

QuizVDS · Answer

Push the rudder in both directions multiple times

QuizVDS · Answer

Fly in a parabolic flight path multiple times

QuizVDS · Answer

Deploy and retract the landing flaps multiple times

Id 59 - SPL - How can a pilot confirm a search and rescue signal on ground in flight?