Which of the following penalties is generally applicable only in criminal cases of copyright infringement?

Imprisonment is a penalty that is specifically linked to criminal cases of copyright infringement. Copyright infringement can lead to both civil and criminal consequences, but imprisonment is reserved for criminal violations. In situations where copyright infringement is deemed to be willful and done for commercial advantage or private financial gain, offenders can face criminal charges, which may result in incarceration.

Other penalties listed, such as injunctions, restitution, and statutory damages, are typically associated with civil cases. Injunctions are court orders to stop a party from infringing on a copyright or to take certain corrective actions. Restitution involves compensating the copyright owner for losses incurred due to the infringement, and statutory damages are preset damages that copyright holders can claim without needing to prove actual damages in a civil case. These remedies are civil in nature and do not involve criminal penalties like imprisonment. Thus, the unique characteristic of imprisonment makes it the correct answer in the context of penalties linked specifically to criminal copyright infringement.