正确答案:
C
解析:
文章第二段第四句话写到“…you’ll often notice that the humans will hold their breath and round their eyes and moths in an ‘on alert’ expression.”接下来作者对这一表情进行了解释,写到“Since these behaviors are expressions of offensive aggression in a canine culture…”这说明主人的这一举动会让狗产生进攻的反应,C正确。