Which of the following connection methods allows a mobile device to share an LTE connection...

Mobile devices can share their LTE or cellular data connection using a feature called tethering, more commonly known as hotspot mode. According to CompTIA A+ objectives on mobile networking technologies, a hotspot allows a smartphone or tablet to become a mini wireless router, broadcasting a Wi-Fi signal that nearby devices can connect to. The LTE (or 5G) connection is then shared over Wi-Fi, enabling laptops, tablets, or other phones to access the internet through the mobile device.

Bluetooth is capable of tethering but provides much lower bandwidth and slower speeds—not ideal for sharing LTE widely. NFC is used for close-range data exchange or payment transactions and cannot share internet service. "Cellular" refers to the phone’s own mobile network connection, not the mechanism for sharing it with others.

Hotspot functionality is specifically built into modern mobile OSs and supports WPA2/3 encryption, password protection, and device whitelisting. This makes it the most common and efficient method to share LTE connectivity with multiple nearby devices.

Thus, Hotspot (D) is the correct answer.