TOEFL Reading: ETS-TOEFL阅读机经 - I3S9N093V6D8733RL$

Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? Incorrect choices change the meaning in important ways or leave out essential information. A. It is fortunate that Moscow's early rulers were descended from an unambitious princely branch with small holdings. B. Moscow benefited from its early rulers' desire to concentrate their energy on the care of their own small properties. C. Moscow was fortunate in that it traced its rulers back to the youngest son of Alexander Nevskii. D. Because most of Moscow's early rulers were junior princes their properties were fortunately relatively small and easy to care for.