Which of these countries represented the easternmost extent of the Greek empire of Alexander the Great and his forces conquered land eastward from Greece to what country? Was it Persia, India, or China?

Of the choices given, the great Macedonian conqueror's eastward expansion reached its final frontier in India. Alexander the Great's ambitious campaign began in 334 BCE, and over the next several years, he successfully conquered the vast Persian Achaemenid Empire. This string of victories brought his forces through modern-day Turkey, Syria, Egypt, and Iraq, culminating in the decisive Battle of Gaugamela in 331 BCE, which effectively shattered Persian power.

Following the defeat of the Persian Empire, Alexander set his sights further east, on territories that had been part of the Persian domain, which included parts of northwestern India. In 327 BCE, he marched into the Indus Valley. The most significant confrontation of this campaign was the Battle of the Hydaspes in 326 BCE against the Indian king Porus. Although Alexander was victorious, the fierce resistance and the sight of Porus's war elephants took a heavy toll on the morale of his soldiers.

Exhausted by years of relentless campaigning and daunted by the prospect of facing the powerful Nanda Empire further east, Alexander's army mutinied at the Hyphasis River (modern-day Beas River). This refusal to march further marked the easternmost point of his conquests. He was forced to turn back, and his vast empire, stretching from Greece to northwestern India, was established. There is no historical evidence to suggest that Alexander's forces ever reached China; the geographical barriers and the sheer distance were immense, and the two civilizations had no direct knowledge of each other at the time.