携帯電話をポケットに入れて歩く「うちに」is using うちに with short "situation" proper?


So I was doing a JLPT test, and have found a question like this:

> 携帯電話をポケットに入れて歩く_____、音楽が再生されたり電話をかけてしまったりするのはよくない。
>
> ところに
>
> うちに
>
> なかに
>
> 最中に

The one that seemed to be fitting was うちに, so I have chosen it and it turned
to be good answer, however I read that うち should be used with long events, so
my question is whether it is proper Japanese or not.




It's proper Japanese and 歩くusually stands for an action that takes a certain
duration.




It's proper Japanese and 歩くusually stands for an action that takes a certain
duration.

