Which of the following statements about stellar parallax is true?
- The amount of parallax we see depends on how fast a star is moving relative to us.
- The closer a star is to us, the more parallax it exhibits.
- It takes at least 10 years of observation to measure a star's parallax.
- We observe all stars to exhibit at least a slight amount of parallax.
- Stellar parallax was first observed by ancient Greek astronomers.