שאלה | Which of the following is incorrect regarding signing apes?

Which of the following is incorrect regarding signing apes?

		The chimps often produced the signs in modified forms, not identical to the standard
		Washoe, and then other chimpanzees in the project, have been claimed to be creative by inventing new terms
		Signing apes' level of deviation from the standard sign is not much different than the devation of signing humans
		While apes have control over their vocalization, they do not have control over their hand gestures, which causes a disturbance