I'm afraid I do not understand the voting options here- we are selecting from rows in which the final column is always 'activity', so we are choosing terms for the first two columns- but what do those columns signify? general and specific / abstract and concrete? "flow quantity" is not comparable to exchange or elementary flow or anything else in the table so I am at a loss. I do think that any system that doesn't recognize quantities as a distinct class is incomplete, but voting for "F" shows a misconception of what a quantity is.

If I were to apply my own perspective, it would be "abstract entity" and "concrete / observed thing" so my votes would be: BGEACDH0. I would prefer "Flowable | Exchange" over "Flowable | Flow" but it is not a choice.