One of the elements constituting the process is ().<br/>A, the same machine tool B, the same fixture C, the same tool D, the<br/>same machining surface A:

梵蒂冈就是在圣彼得教堂附近，是罗马教皇的宫殿，这是一个国中之国。 A: Not far from St. Peter's was the Vatican, the palace of the Pope in Rome, constituting a country within a country. B: Vatican is near to St. Peter's. It is the palace of the Pope in Rome. It is a country within a country. C: Standing beside St. Peter's, Vatican, the palace of the Pope in Rome, is a country within a country. D: Vatican which stands in the neighborhood of St. Peter's is the palace of the Pope in Rome and is a country within a country.