Complex sentence: Yelena asks Yossi to become the new manager, but he turns it down, saying he's leaving the company to become a student; with no other options, Yelena asks Yariv to become the new manager instead.
Split into simpler sentences: Yelena asks Yossi to become the new manager, but he turns it down, saying he's leaving the company to become a student. With no other options, Yelena asks Yariv to become the new manager instead.