Select the most appropriate option to fill in the blank. The ______ conduct of…

Sentence-completion (vocabulary-in-context) items test whether a word's dictionary meaning and connotation fit the tone and outcome described in the sentence -- a near-synonym can still be wrong if its connotation clashes with the sentence's stated result.

The sentence says the minister's conduct "helped in the de-escalation of a very tense situation" -- a positive, conflict-reducing outcome. Only a word describing a tactful, conciliatory manner produces that outcome, so "diplomatic conduct" fits: diplomatic behaviour is careful, tactful, and aimed at avoiding offence or conflict, which is exactly what de-escalates tension.

• "Abrasive" conduct is harsh and grating -- such behaviour would inflame tension rather than ease it.

• "Belligerent" conduct is hostile and combative -- the opposite of behaviour that reduces conflict.

• "Tactless" conduct is insensitive to others' feelings and risks causing offence, not calming a tense situation.