A has no accidentals next to the first quaver on the 3rd beat. However, Chopin put 
before the upper note (c) of the last L.H. semiquaver. As in the previous bar this is a mistake, corrected partly or completely in all the editions:
-
FE moved from the last L.H. semiquaver to the quaver on the 3rd beat;
- GE and EE also added naturals to the R.H. octave.
Compare the passage in the sources »
category imprint: Interpretations within context; Differences between sources
issues: EE revisions, GE revisions, Omission of current key accidentals, Errors of A, FE revisions
notation: Pitch