Answer:
But, you know, um, so, yeah, like, uhh, the answer is none of them.
One should simply say: "I want to go to the moon, but I am afraid that it might be too cold there."
You know what I'm saying, right? And stuff like that.
Explanation:
Of the three options you have provided, letter C is the best -- though it is punctuated incorrectly and it still contains informal speech. That's why I gave you the sentence above.