excel+course - Dynamic Ranges for Data Validation lists

I was trying to implement data validation on a control sheet, and had a situation where I needed the data validation lists to be dynamic - this is because options selected at the start affect the options available later and so the length of the list changes.

So depending on what the first option is, the second could have anything from 3 to 11 options, and so on for the third and fourth.

So, and help on how I can get the data validation lists to display different numbers of options would be greatly appreciated.

Thanks