Alexander sent back home a portion of his army under an admiral called __________

Answer: Option B

Nearchus or Nearchos (c. 360 – 300 BC) was one of the officers, a navarch, in the army of Alexander the Great. He is known for his celebrated voyage from the Indus river to the Persian Gulf following the Indian campaign of Alexander the Great, in 326–324 BC. In 326 BC, Nearchus was made admiral of the fleet that Alexander had built at the Hydaspes.