Q. On which of the following riverbank, the king Alexander erected 12 huge stone altars to mark the farthest point of his advance?
Explanation: When Alexander reached Beas, his soldiers, being war-weary, homesick and diseased, refused to go further. Therefore, he was forced to retreat.
To mark the farthest point of his advance, he erected 12 huge stone altars on the northern bank of Beas.
Source: Tamil Nadu NCERT