The correct option is Shortughai in Afghanistan.

Step-by-Step Explanation:

1. Understanding the agricultural practices of the Harappans:
The Harappan civilization, also known as the Indus Valley Civilization, flourished in semi-arid lands where agriculture required artificial means of irrigation. While archaeological evidence suggests that agriculture was the main occupation, the distribution of water was crucial for cultivating crops.

2. Evidence of Canals:
Traces of irrigation canals have been found at the Harappan site of Shortughai, which is located in present-day Afghanistan. This site was an outpost established by the Harappans, likely to secure access to valuable resources such as lapis lazuli.

3. Regional Variation in Irrigation:
Although canals were found in Shortughai, they have not been commonly found in Harappan sites located in Punjab or Sindh. Archaeologists suggest that ancient canals in those regions might have silted up long ago, or that water was drawn from wells instead. In contrast, at sites like Dholavira in Gujarat, water reservoirs were used to store water for agriculture.