Correct Answer: Attack

Solution : The correct choice is the third option.

Assail and attack both refer to aggressive actions or hostile behaviour directed towards someone or something. They both imply a forceful and often violent approach towards a target.

The meanings of the other options are as follows:

• Perform: This means to carry out or execute a task.
• Systematic: This refers to something that is done according to a system or method.
• Shield: This means to protect or defend.