Autoselect lower options – effective design patterns

I have series of options that I currently render as checkboxes. However, the options themselves "stack" in the sense that selecting one, should auto-select all the options below it.

ex. If we have the following 3 options:

• opt1
• opt2
• opt3

User selection ==> result

• opt3 ==> opt3
• opt2 ==> opt2, opt3
• opt1 ==> opt1, opt2, opt3

The challenge is that some other, previously selected configurations determine whether or not you can select specific options, which has been a serious source of confusion.

If anyone has any ideas of examples of design patterns that would make this a more intuitive experience, I'd really appreciate the feedback!