challenge: How is the distance to M32 estimated using the tip of the red giant branch (TRGB) method?
  
  A. By measuring the graininess of the appearance of its bulge
  B. By analyzing the red giant stars in the galaxy
  C. By estimating the distance based on the appearance of its stars and planetary nebulae
  D. By observing gravitational microlensing events
  Answer: 