The correct answer is: All of the above.
A cross or short-circuit fault occurs when two conductors come into contact with each other. This can happen due to damage to the insulation, or if the conductors are not properly separated. A short-circuit fault can cause a large amount of current to flow, which can damage the cable and other equipment.
An open circuit fault occurs when there is a break in the conductor. This can happen due to damage to the insulation, or if the conductor is not properly connected. An open circuit fault can cause the cable to lose power.
Breakdown of cable insulation occurs when the insulation is damaged and the conductors come into contact with each other. This can happen due to exposure to heat, moisture, or chemicals. Breakdown of cable insulation can cause a short-circuit fault or an open circuit fault.
All of these faults can occur in cables, and they can all cause serious problems. It is important to inspect cables regularly for signs of damage, and to replace any cables that are damaged.