The digitizer is responsible for detecting touch input, so if the phone is not responding to touch, it is likely the digitizer is malfunctioning.

Duplex printing allows printing on both sides of a paper, which can significantly reduce paper consumption and costs associated with buying paper. This makes duplex printing the best feature for cutting costs on consumables.
References:
* CompTIA A+ Core 1 Exam Objectives Section 3.6: Given a scenario, deploy and configure multifunction devices/printers and settings.

Dynamic Host Configuration Protocol (DHCP) allows a networked device to always be assigned the same IP address based on the device's MAC address. DHCP can also assign other network configuration settings to devices automatically.

Testing the power supply first ensures that the correct voltage is reaching all components, which is a common cause of boot issues. Modifying BIOS settings is not possible without a POST. Checking PCIe cards or replacing the motherboard are secondary steps if the power supply is functional. CompTIA A+ Core 1 objectives cover power supply testing as an essential troubleshooting step in system startup issues.

Rapid elasticity is only suitable for a domain whose resource requirements suddenly up and down for a specific time interval. Referring to the question the online retailer wants to migrate to public cloud services during peak season, then wants it to be removed "automatically" when the peak is over.