The answer is probably C. gustan is in plural which matches up with the rest of the sentence
Horizontales
1. Cómo
2.salimos
4. Comes
9. Comen
11. Escribo
13. Aprendemos
15.salieron
16. Comemos
18. Corro
20. Sale
21.corren
22.
23.come
I hope this helps!
Here is what I got as the answer:
Servir —> sirvió
Religious freedom and the chance to practice their beliefs without hindrance.