What is the speed of light and how does it allow us to see the history of the universe?

I - The speed of light is the maximum speed in the universe and allows us to see the history of the universe through the light rays that have been traveling since the universe became luminous.
II - The light rays that we see from distant stars and galaxies have been traveling for thousands or millions of years, so we see them as they were in the past.
III - Astronomers have observed galaxies that are billions of years old and others that are just beginning to form.
IV - We currently know less than 10% of the universe, but astronomers are constantly discovering new structures and phenomena through telescopes and space probes.
a) Only statements I and II are correct.
b) Only statements II and III are correct.
c) Only statements III and IV are correct.
d) All statements are correct.