I made a codepen to demonstrate this behavior: https://codepen.io/kaylee42/pen/Exmqgjq
When I use the lang attribute on a paragraph, Voiceover correctly reads the paragraph in the designated language.
However, when I set the lang attribute on an option within a select (either on the option tag itself, or on a span within the option), Voiceover reads with the pronunciation of the default language (in this case, English). This makes it almost impossible to understand what the options are within the select. The lang attribute should be expose to Voiceover both when it is on the option itself and on a span within the option to improve accessibility of selects.