The correct verb to complete the sentence would be 'quivered' as it correctly associates with the noun 'growl.' 'Growl' stands for 'a deep, rumbling, threatening sound made in the throat by an animal' while 'quiver' denotes 'to shake or move with slight tremulous motion or to tremble, to shiver, to quake, etc.' Thus, the sentence conveys that <u>the campers were quivered(shaken) by the weird rumbling sound which was coming out of the bushes</u>. Thus, option 3 is the correct answer.
