Final answer:
If your cast is falling off, you should contact your healthcare provider for evaluation rather than trying to fix it yourself, leaving it as is, or removing it completely.
Step-by-step explanation:
If your cast is falling off, the correct action to take is C) Contact your healthcare provider for evaluation. It is important not to try to fix the cast yourself, as this could potentially cause more harm than good. Your healthcare provider can assess whether your cast needs to be repaired or replaced. Do not remove the cast completely, as it is crucial for proper healing of the injury. It's also advised not to just leave it as it is until your next appointment, especially if the cast is significantly damaged or loose, as this could affect the healing process.