Answer:
Es
Step-by-step explanation:
Ese bebé es hermoso.
That baby is beautiful/cute/handsome.
In this case the answer is es because it's in the form of ser which is permanent.
Ser - to be (permanent)
Yo soy
Tu eres
Él es
Ella es
Nosotros somos
Ustedes son
Ellos son
Ellas son