Final answer:
The line that shows Othello's anger most vividly is "I'll tear her all to pieces", illustrating his intense rage.
Step-by-step explanation:
The line that shows Othello's anger in reaction to Iago's story is "I'll tear her all to pieces", which demonstrates Othello's anger. This phrase vividly expresses the intensity of Othello's emotions and the physical action he contemplates out of rage caused by Iago's manipulations. The sheer violence of the imagery in "tear her all to pieces" conveys a deeper level of emotional turmoil and fury than the other options provided, aligning it closely with Othello's character as portrayed by Shakespeare in moments of profound rage.