שאלה | Which of the following statements is true?

Which of the following statements is true?

		The correct use of wh-words by apes reveals that they have acquired the understanding of grammatical categories
		The existence of modifiers in the artificial language acquired by dolphins reveals that they can learn a recursive rule
		The ability of the apes to classify lexigrams as food or tools( i.e. edible/ inedible) constitutes evidence for displacement
		The complexity of the communication system of bees reveals that they have a high EQ