To startApple Diagnosticson a Mac, shut it down, then press the power button and immediately hold Command-Duntil diagnostics begin (progress bar appears). This works on Intel and Apple silicon Macs (post- startup options on silicon).
* Option A: Option-D starts Internet Diagnostics (older Macs), not standard Diagnostics.
* Option B: Command-Option-D isn't a valid combo.
* Option D: Shift-D isn't used.
* Option C: Correct per current procedure.References: Apple Support - "Use Apple Diagnostics on your Mac" (support.apple.com/HT202731).

Emergency SOS is a feature on your iPhone that lets you quickly and easily call for help and alert your emergency contacts. To access Emergency SOS on your iPhone, you need to press and hold the side button and one of the volume buttons until the Emergency SOS slider appears on the screen. You can then drag the slider to call emergency services, or continue holding the buttons to start a countdown and an alert sound. If you release the buttons after the countdown, your iPhone automatically calls emergency services. Emergency SOS works differently depending on your iPhone model and region. For example, in India, you need to press the side button three times rapidly to call emergency services. You can also customize the settings for Emergency SOS, such as adding emergency contacts, enabling auto call, and turning off the countdown sound. References: Use Emergency SOS on your iPhone - Apple Support, How to trigger Emergency SOS on your iPhone (and shut it off)