Final answer:
The correct option is b. The bond order indicates the stability of a chemical bond, with higher bond orders suggesting more stable bonds. A bond order of zero means no bond exists, and negative or lower bond orders do not indicate stability.
Step-by-step explanation:
The bond order provides a measure of the stability of a chemical bond between atoms. It is calculated using the molecular orbital model by subtracting the number of anti-bonding ('destabilizing') electrons from the number of bonding ('stabilizing') electrons and dividing the result by two. A higher bond order generally indicates a stronger and more stable bond, while a bond order of zero suggests that no stable bond is formed. Therefore, a negative bond order does not indicate a stable bond, and a bond order of zero indicates that there is no bond at all, rather than a stable one. Hence, the correct options are: b) a bond order of zero indicates a stable bond is incorrect, and c) the higher the bond order, the more stable the bond is correct. The option a) and d) are incorrect as they suggest that negative and lower bond orders indicate stability, which is not true.