1. First I set the ‘Enable USB Debugging option’. I opened the Settings and tapped on the ‘About phone’. Then I tapped several times on the ‘Build Number’. This enabled the Developer option, from where I could enable the ‘Enable USB Debugging option’
  2. I opened the http://kingroot.net site in a browser and downloaded the apk. Then I started the downloaded apk, which rooted my device.
  3. I opened a shell with ‘adb shell’ and executed the ‘su’ command. ‘adb root’ did not work for me for some reason.