Which of the following methods can trigger a victim-operated IED?

A victim-operated improvised explosive device (IED) typically requires a method of activation that also involves the victim's unwitting participation. A pressure release method fits this description because it generally relies on the weight or presence of a person or object to trigger detonation. When the victim inadvertently places weight or pressure on the device, it can activate, thereby making it a "victim-operated" scenario.

In contrast, the other methods listed do not align with the definitions or mechanisms of victim-operated IEDs. Remote control and manual activation imply intentional operation by the user, rather than accidental triggering by the victim. Delaying timers, while they can be used in various explosive setups, are typically employed for pre-planned detonations rather than victim activation. Therefore, pressure release is distinctive in its reliance on unsuspecting victim involvement, making it the correct answer for identifying a method that can trigger a victim-operated IED.