参考答案：C

解析：是非判断。题干：下列关于麦琪姑妈的表述哪句是错误的 a选项为“她名叫Margaret Rarick。”；b选项为“她是我祖父同父异母的妹妹。”；c选项为“她保留自己婚前的名字。”；d选项为“她是L．Rarick的祖母。”。根据原文“…my father had given me the address of his‘Aunt Maggie，’Mrs.．William Rarick of Everson，Washington”；“I learned that Aunt Maggie was my grandfather’s half sister．”；“The lady on the telephone took a long breath and hesitantly said，‘She was my grandmother．’”， Margaret的昵称是Maggie，所以a、b、d选项是正确的；c选项是错误选项；因为保留婚前名字的是L．Rarick，而不是姑妈。