Beginner needs Help with simple Dropdown

[Triplex]

Hello together,
im struggling the Complete Day yesterday with an "simple" Dropdown on a Page:
https://meinkonto.telekom-dienste.de/konto/registrierung/email/index.xhtml?&sid=email
Can please anybody help me, to change this dropdowns?
I tested all, but nothing runs. Recording on Zenno doesnt Record!
Thanks
PS: I tested to click first dropdown and the change innertext, but when i filled all fields and submit, the Site reports an Error!

 

[rostonix]

It's not select.
You need to click on dropdown to open full dropdon list and after that click on any li element

 

[Triplex]

Thanks for the fast Help!
Great