In reference to Xuanzang's accomplishment, the correct answer is option "C".
That is, he helped spread Buddhism to China.
In the year 629, he started a pilgrimage to India that lasted 16 years. He wanted to know more about Buddhism, and it was during those years that he learned not only about Buddhism but also about other cultures of the people he met along the way.
After his return to China, he spends the rest of his life teaching and translating manuscripts and Buddhism became more widely understood in China and elsewhere in the world.
Option A is not possible because the Delhi Sultanate took place between the 13th and the 16th century.
It is not option B because he had no contact with Turkish troops and it was not his objective.
Option D is not possible because Sikhism religion was founded by Gurú Nanak
