Final answer:
The determining factor for reusing a scored drum is the surface finish, as it affects the drum's ability to properly contact the brake shoes and ensure effective braking. Option B is correct.
Step-by-step explanation:
The determining factor for reusing a scored drum is B) Surface finish. While the drum thickness and the number of scoring grooves are important factors, the condition of the surface finish is paramount for ensuring that the brakes function correctly and safely. A drum with a smooth surface finish can properly contact the brake shoes, allowing for effective braking.
However, if the surface is too scored or rough, it may not be able to provide sufficient friction or could cause uneven wear on the brake shoes.