This is the 3146th most frequent Turkish word.
diğerinin
"Of the other" or "the other's".
In this sentence, 'diğerinin' means 'the other's' indicating possession or ownership related to 'tercihi' (choice).
Biri elmayı seçti, diğerinin tercihi ise portakal oldu.
One chose the apple, while the other's choice was the orange.
Here, 'diğerinin' implies 'of the other' referring to possession related to 'on' (it).
Sorunlardan biri çözülmüş, diğerinin üzerinde çalışıyorlar.
One of the problems has been resolved, and they are working on the other one.
In this case, 'diğerinin' conveys 'the other one's' indicating possession related to 'fiyatı' (price).