In the mid-1960's a newly installed radar warning system mistook the

Let's start with this simple example:

• "Bob's fur is brown." - "fur" is a noun, so we use the possessive "Bob's" to qualify that noun

Now consider these two options:

• "Bob barking is keeping me awake."
• "Bob's barking is keeping me awake."

Which is correct? Well, in this case, "barking" is acting like a noun (it's a gerund, if you like the jargon). Just as we need the possessive form when we write, "Bob's fur," we need a possessive to qualify "barking". So the first option is incorrect. "Moon rising" in (C) has the same problem.

And if you're looking for another reason to give (C) the boot, it uses an illogical idiom: "A newly installed radar warning system mistook the moon rising to a massive missile attack..." I can mistake one item for another, but I can't mistake one item to another. You don't have to memorize the idiom; you just need to recognize that the construction in (C) makes it sound as though the warning system is incorrectly transporting the "moon rising" to a "missile attack," which is utter nonsense.

I hope that helps!