@alinephilibert, you could do this as outlined in the image shared below:
In the survey tab of your xlsform:
In the choices tab of your xlsform:

Data entry screen as seen in Enketo:
Reference xlsform:
Aline_issues.xlsx (11.5 KB)
@alinephilibert, you could do this as outlined in the image shared below:

Aline_issues.xlsx (11.5 KB)