Tab shows Win10 as default OS, but computer’s OS is 8.1

My computer’s OS is Windows 8.1



In System Properties > Advanced > Start-up & Recovery > Settings



there is Windows 10 as default operating system. The drop-down menu gives me no other option.



I don’t know why. Is this a problem?



In advance, thank you very much for your assistance.

I assume it was part of the upgrade to win10 placed there ready for the update not a problem