The correct answer is (b), Hieun-Tsang.
Hieun-Tsang was a Chinese Buddhist monk who traveled to India in the 7th century CE. He spent six years in India, studying Buddhist scriptures and visiting various Buddhist monasteries. He also wrote a detailed account of his travels, which is an important source of information about India during the reign of the Chalukyas.
Fa-Hien was a Chinese Buddhist monk who traveled to India in the 5th century CE. He also wrote a detailed account of his travels, but his account does not mention the Chalukyas.
It-Sing was a Chinese Buddhist monk who traveled to India in the 7th century CE. He also wrote a detailed account of his travels, but his account does not mention the Chalukyas.
Matwalin was a Chinese Buddhist monk who traveled to India in the 8th century CE. He also wrote a detailed account of his travels, but his account does not mention the Chalukyas.