i choose violence

https://www.cpmrevenuegate.com/gwa5nwf4?key=e269c1c1f534df24d945d07c63027e14

 The only person with the official authority to order such an execution is the king. At the point that the Mountain killed a Sparrow to protect Cersei, Tommen was still in the process of separating himself from his mother's control. He would not have gone against her wishes and interests so explicitly.

However, this incident was probably at the forefront of his mind when the High Sparrow and/or Margaery recommended that trials by combat be discontinued. He was willing to agree to force Cersei into a trial before septons. This all but ensured that she would be convicted, and so it was the final step in asserting his independence from his mother. But he saw no need to restrict her any further before the trial. What harm could she do? She was already confined to the Red Keep. If he'd been wiser, he would have considered her ability to act through others, and perhaps locked Qyburn up, but Tommen lacked the temperament required to anticipate the actions of evil people. In this, he most resembled Ned, who also underestimated Cersei and paid the ultimate price for his error.