Answer:
The correct answer is: Where thoughts serenely sweet express.
Explanation:
In the last two lines of this excerpt, the author states that the woman's beauty is not just external, as her internal beauty is even more important than her external beauty.
The woman has a virtuous and peaceful mind and an innocent, pure, and loving heart, which actually makes her unique and fabulous. Therefore, we could say that the perfection of the beauty lies in the harmony established between internal and external beauty. These two concepts are strongly related, and we could even say that external beauty is a sign of woman's inner serenity, sweetness, and dwelling.