Which bird, a flightless nocturnal parrot critically endangered with fewer than 300 individuals, is the world's heaviest parrot and can live over 90 years?

• A Kea
• B Kākāpō ✓
• C Tūī
• D Kererū

The kākāpō is a rare, ground-dwelling parrot with a distinctive musty-sweet odour and a unique lek breeding system where males gather to boom and attract females with deep, resonant calls.