[求助]section16-07（没有人问过）

请教大全section16-07题：

A prolific architect who worked from the turn of the century until the late 1950’s, Julia Morgan designed nearly 800 buildings in California, perhaps most notably William Randolph Hearst’s monumental estate at San Simeon.

(A) Julia Morgan designed nearly 800 buildings in California, perhaps most notably William Randolph Hearst’s monumental estate at San Simeon

(B) perhaps the most notable of the nearly 800 buildings in California designed by Julia Morgan was William Randolph Hearst’s monumental estate at San Simeon

(C) of the nearly 800 buildings in California designed by Julia Morgan, perhaps the most notable was William Randolph Hearst’s monumental estate at San Simeon

(D) nearly 800 buildings in California were designed by Julia Morgan, of which William Randolph Hearst’s monumental estate at San Simeon is perhaps the most notable（A）

(E) William Randolph Hearst’s monumental estate at San Simeon is perhaps the most notable of the nearly 800 buildings in California designed by Julia Morgan

答案选A我没有异议，就是不明白“perhaps most notably William Randolph Hearst’s monumental estate at San Simeon”这个部分到底作什么，是独立结构吗？但好像又是在补充说明什么，不懂。。。