1(2) in 
The missing flats before the penultimate demisemiquaver, in spite of their presence in all authentic sources, is almost certainly Chopin's mistake. Descending augmented seconds in scale passages do appear in his works (e.g. in bars 40 and 43), but not in a situation when the upper note of an augmented second would constitute a turning point of a figuration – cf. corresponding places in bars 28, 42 or 65.
If in bar 64 the version with harmonic accompaniment was chosen, the first or third version is to be selected here.
Compare the passage in the sources»
category imprint: Interpretations within context; Differences between sources
issues: EE revisions, GE revisions, Omission of current key accidentals, Last key signature sign
notation: Pitch