Saying "no", correcting assumptions, contrasting identity. The negation wraps around the verb: ne before, pas after. Two things to watch: the elision of ne before a vowel, and what stays put when you negate.
French negation has two parts: ne goes before the verb, pas goes after. Together they sandwich the verb. The trap: when the verb starts with a vowel (or silent h), ne elides to n'. So je ne suis pas (consonant — no elision) but elle n'est pas (vowel — elision). In casual spoken French the ne often drops entirely (elle est pas française), but in writing and formal speech, it stays. Most of the items here use the formal form — that's what your assessments expect.
Which form fills the blank?