Answer:
The correct answer is - option C) sign language.
Explanation:
Washoe was a chimpanzee used in a research experiment. According to Beatrice and Allen Gardner, this chimpanzee is the first non-human to learn and communicative with the help of American sign language. Washoe learned about 350 signs of ASL, an American sign language. It was part of the research experiment on animals.
Thus, the correct answer is - optic C.