Why do I get jealous over a girl even though I don't want to be with her at all?

 The correct answer to the fill-in-the-gap question "She insisted on ___ paying the money" is my.

The phrase "insisting on paying" is a gerund, which is a verb that is used as a noun. Gerunds are often followed by objects, and the object of this gerund is the phrase "paying the money."

To make the phrase grammatically correct, we need to use a possessive pronoun before the gerund. The possessive pronoun "my" shows that the gerund "paying the money" belongs to the subject of the sentence, "she."

The other options, "me" and "mine," are not grammatically correct. "Me" is an object pronoun, and "mine" is a possessive pronoun. Neither of these pronouns can be used before a gerund.

Here is the correct sentence:

She insisted on my paying the money.

I hope this helps!