Where the field meet the rim on 'B' and 'C' appears to be a squared off feature. The other two seem to have more of a rounded connection, more so on 'A'. I would say the following..
A) Concave, Near the rim.
B) Flat, Far from the rim
C) Flat, Far from the rim
D) Most likely Concave, Near the rim.
A) Concave, Near the rim.
B) Flat, Far from the rim
C) Flat, Far from the rim
D) Most likely Concave, Near the rim.
























