challenge: What is a distinctive feature of the adult male spot-winged antshrike's plumage?
  
  A. A clay tinge on the upperparts and tertials with pale clay underparts
  B. A gray tinge on the flanks and undertail coverts with a heavy bill
  C. A black crown with scattered black feathers on the back and white spots on the wing coverts
  D. A cinnamon-tawny crown with no spots
  Answer: 