C. You must live up to your principles- you must give your daughters the same liberty as you advocate for other women.
Explanation:
The doctor said when Clara was twenty, her father did not object to her learning chemistry or playing instruments. She would have assumed that to be very cruel if he had objected.
When the father looked at Clara's dress, he thought it was torn and asked her about it. She said it was a divided skirt. Her father replied that her mother would not have liked that.
Finally, he says, seeing their mistakes, he had realized his mistake.
