What is the correct order of flats?

A:
BAEDGCF
B:
BEADGFC
C:FCGDAEB
D:
BEADGCF

The correct order of flats in the context of music theory is represented by option B:

BEADGFC

This is a mnemonic for the order of flats as they appear in key signatures in Western music notation. Each letter represents a flat note, and they always appear in the same sequence:

B - flat
E - flat
A - flat
D - flat
G - flat
F - flat
C - flat

So, when key signatures are written on the staff, flats are added in this order. For example, a key signature with two flats would contain B-flat and E-flat, while a key signature with five flats would contain B-flat, E-flat, A-flat, D-flat, and G-flat.