Hello @Ahunam_Chidinma
Welcome to the ODK forum. We're glad you're here and thanks for the introduction.
Regarding your issue, that is how it works. "a" is showing in your database because it is the identifier if the specific choice. In your case, it seems you want to have both name and value match to ease the analysis on your end. You can learn more about this here: https://docs.getodk.org/form-question-types/#single-select-widget.
If you have a lot of data already collected, then you will need to look at data processing options. Checkout this link Web-based Stata cleaning code generator