A little from column (a) and a little from column (b). I have my doubts about Philemon, for example, but I haven’t taken the trouble to vet those doubts, because there is nothing in it relevant to my work (no discussions relevant to the historicity of Jesus). I have independently confirmed to my own satisfaction (via stylistic, literary, and historical analysis) that the other six were written by the same author, and that this was not the author of the Pastorals, the Deuteropaulines, or 2 Thessalonians (or Hebrews, but that doesn’t claim to be by Paul). Although there is room still to convince me otherwise, since my examination wasn’t exhaustive, just enough to satisfy me that the widest consensus is probably correct.

Now, one could still argue that though those six were written by the same author, nevertheless they are fictional, but that cannot follow from their content, which is perfectly explicable without that hypothesis (I have satisfied myself that arguments to the contrary are invalid, e.g. Detering’s case is built on fallacious reasoning), so one would need some sort of external evidence to conclude that, and there isn’t any that I know of. Moreover, contra Brodie, they simply do not look like fictional letters–I’ve read a lot of examples of the latter from antiquity, and they have little in common in style and content with letters like Paul’s (the one argument that they are unusually long has a more plausible explanation in the fact that we have evidence they are actually stitches of several letters, which evidence would not exist if they were fictional, but is exactly what we’d expect if real letters were stitched together).

So I am sufficiently confident at least those six are by the Paul they claim to be written by and were written in the 50s AD.