Answer:
B.
Explanation:
In the given paragraph, the author has used the word 'gibberish' to emphasize the complexity of spoken sounds.
In the given passage, the author is trying to educate it's readers about how dogs discern the sounds of people and how they take those sounds and response to them.
The word 'gibberish' means a nonsensical speech, a speech that doesn't make any sense. The author has used the word 'gibberish' in the given context to show how complex our sounds are and how careful we need to be to make use of our sounds to teach our dogs.
Therefore, B is the correct option.