—mi padre, juan, tiene una hermana en cuba. ella es sandra. ellos tienen el pelo
—¿cómo es sandra?
—es

group of answer choices

castaña; bonita

castaño; bonito

castaña; bonito

castaño; bonita

According to the context, for the sentences to be complete we must add the missing adjectives in the blank spaces:

—Mi padre, Juan, tiene una hermana en Cuba. Ella es Sandra. Ellos tienen el pelo castaño.

—¿Cómo es Sandra?

—Es bonita.

Translation:

—My father, Juan, has a sister in Cuba. This is Sandra. They have brown hair.

—What is Sandra like?

—She is pretty.

An adjective can refer to a specific characteristic of the noun and they usually coincide in gender and number with the noun.

Therefore, we can conclude that an adjective is the part of the sentence that qualifies the noun, and that provides additional information.

Learn more about adjectives here: link

Ellos tienen el pelo castaño.

Es bonita.

Explanation:

Pelo is a singular masculine noun which requires a singular masculine adjective "castaño".

Sandra is a female person, requiring a singular feminine adjetive "bonita".