Correct Answer  Option 3 : Distance; Time

Length is a measure of the size or distance between two points.
 The SI unit of length is the meter (m).
Light Year:
 A lightyear is a unit of distance.
 A lightyear is the distance a beam of light travels in a single Earth year, or 6 trillion miles (9.7 trillion kilometres).
 One lightyear is the distance travelled by light in a vacuum in one year.
 A lightyear is a convenient unit of measurement of large distances.
 Generally, a lightyear is used to represent astronomical distances.
 1 light year = 9.46 × 1015 m.
Thus, the lightyear is a measure of distance, not time.
Parsec (parallactic second):
 It is the largest practical unit of distance used in astronomy.
 It is defined as the distance at which an arc of the length of 1 astronomical unit subtends an angle of 1 second of arc.
 1 parsec = 3.08 × 1016 m
Astronomical unit:
 It is defined as the mean distance of the earth from the sun.
 It is used in astronomy to measure the distance of planets.
 1 astronomical unit = 1 AU = 1.496 × 1011 m