If a worshipper forgetfully appends a Surah before reciting Surah al-Fatihah in a rak'ah, what must they do?

The Necessary Acts of Prayer (واجبات الصلاة) Part 1: Recitation

• The prayer is void and they must restart it.
• They must perform Sujud al-Sahw at the end of the prayer.
• They must wash their face.
• Nothing, as sequence is only optional.