This is the 5129th most frequent Russian word.
напитком
A drink or beverage.
In this example, 'напитком' is in the genitive case 'напитка', indicating possession or association in the context of the choice.
Мои друзья удивились моему выбору напитка.
My friends were surprised by my choice of drink.
In this sentence, 'напитком' is used in instrumental case as it describes the means of enjoying.
Я наслаждаюсь этим прохладным напитком.
I am enjoying this refreshing beverage.
Here, 'напитком' is transformed into its nominative case 'напиток' to denote the subject.