Answer:
C) While Nora had never really considered herself an unhappy woman
because of her nice home and even nicer husband.
Step-by-step explanation:
There is no subject and verb. There is Nora and her considering herself this and that, but it says "While Nora", meaning that something has to come after that to contrast this statement. The word "while" is a subordinating conjunction, so the phrase that goes along with it is a sentence fragment.