Tengo muchas amigas y ellas son .
simpáticos
simpática
simpáticas
2. Mis profesores son .
buenos
buenas
bueno
3. En la biblioteca hay libros.
mucha
mucho
muchos
4. La cafetería es .
granda
grande
gran
5. El director es .
francés
francesa
franceso

corras is the only one that is informal but doesn't follow the suffix rule. correr is the verb. corre is the formal verb form. corra would be used as the formal is corre ended with an a.

your best bet would be corras, it's the only one that is informal but is still wrong