<p>I remember the requirement two years ago being,
1ab must be tested out of together (no just 1a or 1b)
1ab is required to test out of 1c
1abc is required to test out of both 2ab</p>
<p>I could be wrong though. I am pretty sure that you can’t test out of 1a alone though. BTW, I tested out of 1ab and 2a, and I’ve heard of people testing out of 1ab and 1abc.</p>