The correct answer is
D. I really don't like that sweater very much because its rough fabric makes my skin itch.
If you are using the contraction it's, know that it means it is, which doesn't make sense in this sentence.
Also, in this specific sentence there shouldn't be an apostrophe in the verb makes.
Hope this helps! :)
Even though you didn't give us the fragment with the comma slice, it isn't really necessary here as we can answer just based on these 4 options here. All options apart from the second one are correct - only the second option doesn't fix the mistake of the comma splice, whereas the other options do but connecting the sentences properly.