If you wish to install in UEFI mode and don't care about keeping the ability to boot one of the existing systems, you have the option to force that here. If you wish to keep the option to boot an existing operating system, you should choose NOT to force UEFI installation here.
Ma yella tebɣiḍ ad tesbeddeḍ deg uskar UEFI, ur d-tecliɛeḍ ara seg uḥraz n tezmert n usenker n yiwen seg yinagrawen i yellan, tzemreḍ ad t-tḥettmeḍ sya. Ma yella tebɣiḍ ad tḥerzeḍ taxtiṛit n usenker n unagraw n wammud, ilaq ad tferneḍ UR ttḥettim ARA asebded UEFI dagi.