In order to make it all the way from the opening to the detector, a wave has to travel through air, glass, water, plastic, and vacuum.
-- The siren and the tuning fork are sounds.
-- Sound cannot travel through vacuum.
-- That knocks out choices B, C, and D.
The answer is A.
Note: Making a big exception here. We don't do test questions on Brainly. That would be cheating. Don't let me catch you doing it again.
