The Ottomans could provide Italian scholars with many of the Greek and Roman texts they wanted because?

Because they have conquered Constantinople, where most of these texts were preserved. But, not only Constantinople, but many other important cultural centers, such as Nicaea, Antioch, etc.

Explanation:

When the Ottomans captured Constantinople in 1453, they managed to capture all the wealth that was preserved there. Among the other things, they have captured a large cultural treasure, that was kept there for centuries. That of course included texts, manuscript from the Ancient period.