Correct Answer: Crafty

Solution : The correct choice will be the fourth option.

Artful: It means clever, skilful, or adept cunningly or deceptively; characterized by cunning or trickery.

Crafty: It means clever deceptively or slyly.

In this context, crafty aligns closely with the meaning of artful as both convey a sense of cleverness, especially in a manner that may involve deception or manipulation.

The meanings of the other options are:

Prudent: It denotes wise, cautious, or sensible in practical affairs; showing good judgement.

Benign: It denotes kind, gentle, and favourable; having a gentle disposition or showing kindness.

Ignorant: It denotes lacking knowledge, awareness, or education; uninformed or unaware.

Therefore, the correct answer will be crafty.