Which flightless, nocturnal parrot, the world's heaviest, is critically endangered with a population of fewer than 300 and has a distinctive musky odour?

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

The kākāpō is a large, ground-dwelling parrot that evolved in a land without mammalian predators; it uses a unique lek breeding system where males gather to emit deep booming calls to attract females.