Answer: 3.To dress up and parade certain streets for an hour every day, to stand talking in doorways, or drive out in a fine carriage, was not the sort of exercise she liked, and Fan would take no other.
Explanation:
The sentence that best supports Polly’s reasons for keeping her outings a secret from Fan was "To dress up and parade certain streets for an hour every day, to stand talking in doorways, or drive out in a fine carriage, was not the sort of exercise she liked, and Fan would take no other".
From the text, we can see that Polly's idea of an exercise was quite different from what Fan wanted. This is supported by the above answer and this resulted in her keeping her outing as a secret.
