VFR comms without question. Not only is it very sensible to have VFR and IFR comms split into two £67 exams, i would have thought it prudent to split the massive undertaking up a little further "advanced transponder" should really be an exam in it's own right.
On a different note, i have no idea what a "microtesla" may be but i'm quite sure that there are 6 of them.