Question

1. mis padres juegan ____ cartas.

al
a las
a los

Explanation:

In Spanish, "jugar a las cartas" is the correct phrase for "to play cards". "Cartas" is feminine plural, so we use "a las" (preposition "a" + definite article "las" for feminine plural noun). "al" is "a + el" (masculine singular), "a los" is "a + los" (masculine plural), which don't match the feminine plural "cartas".

Answer:

B. a las