Explanation
The most common reasons you may be seeing the "No Signal" message: The projector and the source device are not connected correctly.
The first action should be to check the video cable and replace it if necessary, as the error message suggests that the projector is not receiving a signal from the laptop. Verifying that the projector is turned on and checking the bulb would come after verifying the video cable.

Explanation
The appropriate connection types for connecting an external keyboard to an Android tablet are USB-C and Bluetooth123.

Explanation
A router is a device that connects one or more networks, such as a home or small office network, to the internet. It allows multiple devices to share a single internet connection and provides network address translation (NAT) to enable communication between the devices on the local network and the internet. A hub, Ethernet gateway, or wireless access point does not provide this functionality.
A router is the most likely device to be used to connect one or more devices to the internet in a SOHO. A router can provide network address translation (NAT), firewall protection, and other features that are important for securing and managing a network. References: CompTIA A+ Certification Exam Guide, pg. 355

Explanation
Rapid elasticity would be used by an online retailer to quickly add more web servers during peak sales times.
References: CompTIA A+ Certification Exam Guide, Exam 220-1001, Page 405

Explanation
Switches only send data to the specific computer, while hubs send data to all computers inside the network.
References: CompTIA A+ Certification Exam Guide, Exam 220-1001, Page 323