The method of stellar parallax
A) can be used to measure the distance to stars in distant galaxies just as it can be used for stars in the Milky Way Galaxy.
B) can be used for distant galaxies but only when used with giant molecular clouds (which can be seen at such distances), not with stars.
C) cannot be used for distant galaxies because redshift spectra are inherently imprecise at such distances.
D) cannot be used for distant galaxies because of the difficulty of resolving the spectra of individual stars.

Question

Quizplus · Accepted Answer

The method of stellar parallax is effective for measuring distances within the Milky Way Galaxy but not for distant galaxies, primarily because it relies on detecting the apparent motion of a star against distant background objects as Earth orbits the Sun. At the vast distances of other galaxies, this apparent motion is too small to detect, making it impractical to use stellar parallax for such measurements.

The Method of Stellar Parallax