Option 1 -> "Unsettling" means disturbing or causing anxiety, which contradicts the positive outcome of inspiring confidence.
Option 2 -> "Dismissive" suggests showing that something is unworthy of consideration, which wouldn't inspire confidence in others.
Option 3 -> "Reassuring" means providing comfort and removing doubts, which perfectly aligns with inspiring confidence during a crisis.
Option 4 -> "Indifferent" means showing no care or concern, which would not inspire confidence in a crisis situation.
Hence, Option 3: reassuring -> Her calm demeanour served as a source of comfort and confidence for everyone during the crisis, making it the perfect word to describe how she positively influenced those around her -> correct