Dropdown

I can't seem to find a way to alter the dropdown so that subsequent dropdown selections (or options) are limited by what's already been chosen in the previously selected dropdowns.

For example, I want to compare A-B-C-E. Which one is the best?

A (Options 1, 2, 3, 4) - if 2 is chosen then,
B (Options 1,3,4) - if 3 is chosen then,
C (Options 1, 4) - if 1 is chosen then,
D (Option 4) -

thecarriers