Which of the following components is NOT part of a semi-automatic handgun?

The trigger guard is indeed a component of a semi-automatic handgun, serving to protect the trigger and prevent accidental discharges. In contrast, the frame, slide, and barrel are all integral parts of a semi-automatic handgun. The frame houses the operating components and provides structural support; the slide is essential for the cycling of the action and loading of rounds; and the barrel directs the bullet's path upon firing. Each of these components contributes critically to the handgun's functionality, whereas the trigger guard's primary role is safety. Recognizing this distinction clarifies the composition of a semi-automatic handgun.