C for me. Clearly at the top it's for sale and the QR code is going to be closest to someone walking up. They're not having to step foot on the property to scan it.
I like F but I would leave the "for sale" the same size it currently is. But I would make swap the sizes of the other 2 parts make the realestate company part about half as small and the phone number and your name about twice as big.
Only thing I would care about is making it known it is for sale and how to contact you.
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