Final answer:
The Mongols and traders from the Ottoman Empire were the challenges to India after the death of Timur Lenk.
Step-by-step explanation:
After the death of Timur Lenk, the two challenges to India were the Mongols and traders from the Ottoman Empire.
In the late 14th century, Timur (also known as Tamerlane) attacked the city of Delhi, the capital of the Muslim-ruled Delhi Sultanate. He successfully defeated the sultan's army and destroyed Delhi.
Meanwhile, trade with the Ottoman Empire posed a challenge to India. The end of the Pax Mongolica in the 14th century led to increased risks and costs associated with caravan trade, prompting Europeans to seek alternative ways to reach East Asia.