interaction design - Radio buttons or Toggle switch for one out of two options?

I am a bit confused on what should be used when you have to select one option out of the two possible options. Working on a touch screen interface

For ex 1- Selecting a Tax type in a retail store, Options are Inclusive and Exclusive

Ex 2- Selecting a discount type

I can't figure out how one option can be preferred over the other in cases like these. So, can anyone tell me a reason or two to choose one over another in similar cases like mentioned in examples.

Answer

I think you're referring to toggle switches here. That being said, Radio buttons let users select one option from two or more choices whereas a toggle switch mimics a physical switch that allows users to turn things on or off.

You can also refer to these UX guidelines by Microsoft on when to use which control:

Guidelines for toggle switch control

Guidelines for radio-button control

Edit: As we're dealing with just two options, you can use radio button for touch interface provided they are easy to tap.

From the screenshots, it seems you're working on a non-touch UI (taking a hint from dropdown). This and that we're dealing with just two options here, I would recommend radio-buttons for this use case. Had it been more than three options, I would have gone ahead with a Toggle Button (not a switch)