Am I mishearing 这房子里究竟哪一样, and if not, how do I understand it?

Question

After moving to a new place, friends are visiting Lao Wang. It turns out his wife has decided the curtains, carpet, etc.

……老王回答：“所有的家具都是我太太挑选的。”我终于忍不住问道：“这房子里究竟哪一样。是你挑选的呢？”老王思考了片刻，说：“我太太。”
_{HSK5 past exam H51224, questions 31 and 32}

In this listening problem, I don't quite understand the nuance of the last question. I'm not 100% sure I'm hearing it correctly. I'm expecting this to be a joke of some kind. It says something like:

I finally couldn't help but ask: "This place is the same. Did you choose it?" Lao Wang thought for a bit and replied: "My wife."

This doesn't quite make sense to me. I feel like I'm missing something, noting it's possible I misheard something. (I was expecting a joke along the lines of "So, what about this place did you choose?" "My wife.")

Question: Am I mishearing 这房子里究竟哪一样, and if not, how do I understand it?

Answer 1

I think the period mark is a typo, the sentence only makes sense without it.

这房子里究竟哪一样。是你挑选的呢 (X)

这房子里究竟哪一样(東西)是你挑选的呢 (O) - What (thing) in the house was actually chosen by you?

The punchline is '我太太' (my wife) -- The only thing in the house that was chosen by him was his wife

Answer 2

老王回答：“所有的家具都是我太太挑选的。”

我终于忍不住问道：“这房子里究竟哪一样，是你挑选的呢？”

老王思考了片刻，说：“我太太。”

My translation goes like this

Lao Wang replied: "All the furniture was my wife's decision." 

I finally couldn't help asking, "Is there anything in the house that was your decision?" 

Lao Wang thought for a moment and said, "My wife."