Question

what forced europeans to look for other routes east?
land routes were closed off by ottoman turks.
europeans were conquered by ottoman turks.
europeans lost interest in eastern products.
land routes no longer led to needed goods.

Explanation:

The Ottoman Turks closed off land routes. This made it difficult for Europeans to access Eastern products via the traditional over - land paths. As a result, they had to seek alternative routes, such as sea routes. The other options are incorrect. Europeans were not conquered by the Ottoman Turks in a way that directly forced them to look for new routes. And Europeans did not lose interest in Eastern products; in fact, they still desired them. Also, the land routes were closed rather than not leading to needed goods (they were closed by an external force - the Ottoman Turks).

Answer:

Land routes were closed off by Ottoman Turks.