Most of the Harappan sites are located in which among the following regions:

Semi-arid region

The correct answer is Option (1) → Semi-arid region

".. Most Harappan sites are located in semi-arid lands, where irrigation was probably required for agriculture. Traces of canals have been found at the Harappan site of Shortughai in Afghanistan, but not in Punjab or Sind. It is possible that ancient canals silted up long ago. It is also likely that water drawn from wells was used for irrigation. Besides, water reservoirs found in Dholavira (Gujarat) may have been used to store water for agriculture."