Who took revenge on Muhammad bin Qasim?

Answer 1

Muhammad bin Qasim was a seventeen year old Saudi Arbian born general who brought Islam to what is present day Pakistan. It appears that one of two outcomes followed.

During the conflict, Qasim's opponent Raja Dahir was killed. His two daughters were taken hostage and sent to the Khalifa Sulayman ibn Abd al-Malik. The daughters reported to Sulayman that Qasim had violated them before sending them to the Califf. Enraged, the Califf ordered Qasim arrested, and while being transported back to face the Califf, Qasim died.

or

Khalifa Sulayman ibn Abd al-Malik was the enemy of Qasim's uncle and began rounding up all who supported him. Qasim was imprisoned and tortured in Iraq, and there died.

No one knows which account is true, but it appears that Khalifa Sulayman ibn Abd al-Malik is the person who ordered Qasim's death in either case.