The map shows the Gupta Empire. A map titled Expansion under Gupta Rulers. A key shows rulers and area of expansion by color. Chandra Gupta I (circa 320 to 35 C E) in blue. Samudra Gupta (circa 335 to approximately 74 C E) in purple. Chandra Gupta I I (circa 380 to approximately 415 C E) in green. Blue shading begins along the northern border of India and extends south to Bodh Gaya. A line for label Ganges Basin is in the northeastern section of the blue area. Purple shading includes the region along the eastern coast to Bodh Gaya and northern India. Green shading extends from the purple region in northern India south and west to the coast of the Arabian Sea.

Chandra Gupta I expanded the empire along which physical feature?

the Himalayas
the Arabian Sea
the Ganges Basin
the Bay of Bengal