Correct option is D. Lightyear
Parsec and light year are those practical units which are used to measure large distances. For example, the distance between the sun and earth or other celestial bodies. So they are the units of length, not time. Here, second and year represent time.
Important point: 1 light year (distance that light travels in 1 year with speed $$=3 \times 10^8 m/s$$=$$9.46 \times 10^{11}m$$ And 1 par see $$=3.08\times 10^{16}m$$