is this correct?

¿Adónde van algunos niños antes de ir a la escuela primaria?
a. Van al patio de recreo
b. Van a la guardería infantil
c. Van a la universidad
d. Van a la oficina

B?

Yes, option B is correct. Some children go to the "guardería infantil" (daycare) before attending primary school.

If you wanted to verify the answer, you could have done the following steps:

1. Translate the question: "¿Adónde van algunos niños antes de ir a la escuela primaria?" means "Where do some children go before going to primary school?"
2. Read each option:
a. "Van al patio de recreo" means "They go to the playground."
b. "Van a la guardería infantil" means "They go to daycare."
c. "Van a la universidad" means "They go to university."
d. "Van a la oficina" means "They go to the office."
3. Analyze the options and determine which one makes sense based on the question. In this case, since it's referring to children before primary school, option B (going to daycare) is the most likely answer.