Question

select the possessive adjective. (ellos) ______ madre
sus
mi
vuestros
su

Explanation:

To solve this, we analyze the possessive adjectives in Spanish. "Ellos" (they, masculine plural) has the possessive adjective "sus" for plural nouns (here, "madre" is singular but "sus" can also be used for plural ownership contextually, or note that maybe a typo but "sus" matches the plural subject "ellos" for their mother(s). "mi" is for "I", "vuestros" for "you (plural familiar)", "su" is for singular (él/ella/Ud.). So "sus" is correct as it agrees with the plural subject "ellos" (their mother(s)).

Answer:

A. Sus