"She is no less optimistic than her elder sister." The sentence means that
【正确答案】 C
【答案解析】考查短语no less...than的用法。no less...than表示肯定两者,意为“和……一样”,因此答案为C。D中的no more...than与no less...than形成反义词组,意为“和……一样不”,否定两者。