What type of safety is located on the top of the receiver and operated by sliding it with your thumb?

The correct answer is the slide/tang safety, which is typically located at the rear or top of the receiver on many firearms. This type of safety is engaged or disengaged by sliding the mechanism with your thumb, providing the shooter with a direct, tactile indication of whether the firearm is in a safe or fire mode. Its design allows for easy manipulation without requiring the shooter to reposition their hand significantly, ensuring quick accessibility while maintaining a proper grip on the firearm.

In contrast, the cross-bolt safety is typically found on some shotguns or rifles and functions differently, as it is pushed in or out, rather than sliding. A manual safety generally refers to any safety feature that a shooter must actively engage or disengage, which could encompass various types of safeties, but is not specific to the sliding operation described. Lastly, the trigger safety is a mechanism designed to prevent accidental discharge by blocking the trigger unless the safety is disengaged by pressing a specific part of the trigger itself, which does not align with the thumb-operated sliding action in the question.