By default, when text is converted to a two-column layout, the first column is wider than the second

You are troubleshooting a mobile device with no sound output from the headset or external speakers. Which of the following steps should you take first?

a. Verify the physical volume control is turned up. b. Reset the device to factory defaults. c. Perform a manual OS update. d. Close any unused apps.

Name an input device.

What will be an ideal response?