This question was doozy. I wanted to share with others my notes on how I got the correct answer during Blind Review. During the timed test, I would most likely skip this one and save it for later. It took some time for me to translate the stimuli into a format that made sense to me.

At first, I also thought that the sentence in question was the conclusion of the argument. I had to ask myself what the author was really trying to convince me of; that it is not necessary to be at home to be in your house? No. The author was trying to convince me "You can be in your backyard and not at home, that is, not in your house."

So, my notes to decipher it and arrive at the correct answer looked like this:

Difficult argument structure. I think it is C because if we rewrote the stimuli into easier language to read and understand it would look like:

Conclusion: You can be at home if you are in your backyard but not in your house.

Premise: For example, you can also be in your house but not at home if you rent your house to others. (If you're the landlord you could be in the house to do repair work, but you are not 'at home' because you don't live there)

Premise 2/Subconclusion: Therefore it is not sufficient to be in your house to be at home.

Translation of answer choice C: Claim is compatible with the truth or falsity of the conclusion = This is a premise/sub conclusion