How do I set it so that it does not save what has not been selected

Hello everyone!

I have some fields in the form that only show when an option is selected in another field.
I put rate A
and it shows "T sale A" and "T cost A" and if I put rate B, the options of B.

The problem is that he keeps everything from A and everything from B and I just want him to keep what is shown, not what is shown and what is hidden, because it does not make sense.

I have put in:
Load states
Hidden
1
When the form is loaded, the field will be hidden.

and so I hide it until the rate is selected.

How do I set it so that it does not save what has not been selected?
I have not seen any thread to help me.

Thanks in advance.