By hook or by crook means by any possible means. The correct answer is this meaning because the expression is used figuratively, not only by its literal words.

Examples:

• They promised to finish the bridge by hook or by crook.
• In an HSC essay, By hook or by crook can express this meaning: by any possible means.
• When this expression appears in a passage, connect By hook or by crook with the idea of by any possible means.