Control Choice - Do you know when to use options group Radio Buttons instead of ComboBox?

When the options are static items (not database driven) and they can fit on the screen (about 2-5 items), they should be radio buttons.

For a ComboBox, user needs 2 clicks to change the value:

1. Click the ⌄ button to see the available options
2. Then click the option to select

For an options group, user can see all the available options without clicking, and select the option with just a click.