The correct answer is: We cannot tolerate such a heinous act of violence.
Tolerate means to allow or accept something that you do not like or agree with. Heinous means extremely wicked or evil. Violence is the use of physical force against another person, usually to hurt or kill them.
The other options are not as appropriate in this context. Consider means to think about something carefully. Important means having a great deal of significance or value. Commit means to do something wrong or illegal. Magnificent means very impressive or splendid. Pardon means to forgive someone for a crime or offense. Neglect means to fail to take care of something or someone. Insignificant means not important or significant.
In this context, we cannot tolerate such a heinous act of violence. We must take action to stop violence and protect those who are being harmed.