Answer:
Maritza es una compañera de clase de Verónica.
Step-by-step explanation:
The translation for the sentence above is:
Maritza is Veronica's classmate.
The other options would not make sense, I'll explain why:
1) Maritza es una profesora (teacher) de clase de Verónica.
Profesora de clase sounds redundant and incorrect in Spanish.
2) Maritza es una excelente (excellent) de clase de Verónica.
Excelente de clase is incomprehensible, it doesn't exist. If translated, it would read something like "Maritza is excellent of Verónica's class".
3) Maritza es una se llama (is called) de clase de Verónica.
Once again, this doesn't make any sense in Spanish. The sentence already has a verb that is in need of a noun, so adding another verb is incorrect.