I assume you are using Oracle Configurator Developer where you have the ability to import your model BOM, add rules, and build user interfaces. If this is true, then you can do exactly what you want with the use of Display conditions in the User Interface.
1. Create boolean feature in your model called "SHOW_OC_3" and "SHOW_OC_4"
2. Write statement or logic rules in your model to imply SHOW_OC_3 and another for SHOW_OC_4 (I am assuming there are different rules for both of the OCs).
Example might be:
AnyTrue(OptA, OptC) Implies SHOW_OC_3;
3. In your UI, find the page that contains the Option Class UI Element. on this element, you can edit and add a display or enabled condition. You would hook the Display/Enabled condition to be based on the True/False state of SHOW_OC_3.
E.g. SHOW_OC_3.SelectionState Is True
When you test your model in Configurator Developer - you will see that OC3 is enabled or completely hidden until OptA or OptC are selected. Whether it is Disabled or Hidden is based on whether you used a Display Condition or Enabled Condition in step 3 above.