Allen and his lab partner each held a tuning fork, frequency 440 hz, in their hands. allen tapped his tuning fork with a mallet and they listened to the sound it made. "wait a minute! " exclaimed allen's partner. "my tuning fork is vibrating too! " sure enough, both tuning forks were vibrating although only allen hit his with the mallet. how can you explain this? a) sound waves are transferred to the tuning fork. b) sound particles caused the second tuning fork to vibrate. c) sound energy travelled as waves from one tuning fork to the other. d) sound energy travelled as particles from one tuning fork to the other.