If the speed of light is 3.00 x 10⁵ km/s, how many kilometers is 1 light-year? (Note: One year contains 3.16 x 10⁷ s.)
a) 9.48 x 10¹2 km
b) 3.16 x 10⁷ km
c) 3.00 x 10⁵ km
d) 9.48 x 10¹5 km