Final answer:
The statement is true; crusaders and other interactions between the Islamic and Western worlds facilitated the transfer of important scientific and medical knowledge that had been preserved and expanded upon by Islamic scholars, influencing the Renaissance.
Step-by-step explanation:
Returning crusaders indeed brought back scientific and medical knowledge from the Islamic world. During a period where Europe experienced the so-called intellectual 'Dark Ages' after the fall of Rome, Islamic scholars played a crucial role in preserving and advancing knowledge. Scholars such as Al-Khwarizmi—the inventor of algebra—and Ibn Sina—renowned astronomer and physician—made significant contributions in various fields.
Meanwhile, Arab mathematicians were fascinated by the Indian number system and its concept of zero, this eventually paving the way for the adoption of Arabic numerals in the West.
The transfer of this knowledge, accumulated and enhanced by Muslim scholars, was accelerated through interactions such as trade routes and the Crusades. Furthermore, when Byzantine scholars fled to Europe, they brought with them the knowledge of ancient Greece and Rome, greatly impacting the Italian Renaissance. Therefore, the assertion is true.