Find out the odd one

Hiuen-Tsang Chinese Buddhist monk who traveled in India; documented Indian society, religion, and politics in his work Si-Yu-Ki ✅ Accurate
Al-Biruni Persian scholar who wrote Tahqiq ma li-l-Hind, a detailed account of Indian culture, science, and society—not specifically about Harshavardhana ❌ Slightly inaccurate (not focused on Harsha)
Megasthenes Greek ambassador to Chandragupta Maurya; wrote Indica about Indian society—not Indo-Persian relations ❌ Incorrect attribution
Ptolemy Greco-Roman geographer who wrote Geographia, including maps and descriptions of India ✅ Accurate