Answer:
Explanation:
1. Hoy ____ el cumpleaños de mi prima Rosa.
2. Mi hermana __ es __ muy bonita.
3. La Señora Sandoval __ es __ la profesora de español.
4. El camarero __ está __ nervioso.
5. Mi familia __ está __ en Portugal.
6. La leche __ está __ caliente.
Since "ser" is more of a "permanent thing" or "Identity" we can conclude that estar is used as a "condition" or "temporary thing"
For example: Yo soy (ser conjugated) Jay ( I am Jay) - My name is an identity and is permanent
Yo estoy (estar conjugated) bien (I am good/well) - I am feeling an emotion and an emotion can be considered a condition or temporary.
(c) el volante Is the correct answer