Greek writers Strabo and Justin called Chandragupta Maurya —
Explanation
Correct answer: Seleucus I Nicator. Chandragupta Maurya fought Seleucus I Nicator around 305 BCE. Their settlement transferred eastern territories to Chandragupta and established diplomatic relations between the Mauryan and Seleucid courts. Therefore this option matches the accepted historical association and chronology. Alexander died before the Mauryan–Seleucid settlement, Antiochus I belongs chiefly to Bindusara’s diplomatic context, and the other names do not fit the chronology and identity of Chandragupta’s opponent. Each incorrect option may refer to a real feature of ancient Indian history, but it is shifted to the wrong ruler, place, title, event or numerical detail. The answer should be chosen from the specific evidence asked in the question, not from a broad association with the Mauryan period.