The correct option is B Outwardly imposing but easily defied.
Option B is the correct answer. Mrs. Quabarl is very vocal about her demands and imposing in her wishes as stated in the passage. But she is also docile and surprised when she is defied, though she speaks nothing of it. There is no indication of her being selfish, or bitter, neither imprudent. Thus, options A,C and D are incorrect.