It is easy points if you know any spanish

Here is a hint to this question

son means are

es means is

esta means he/she is

and estan means they are

Los maestros inteligentes

Teachers smart

lets take this in english terms would which one would make sense

Teachers are smart

Teachers is smart

Teachers he is smart (just took one pronoun)

Teachers they are smart

The one that says teachers are smart makes the most sense there you have your answer :son

btw i did not use google translate 4 this i actually learn spanish in school

-hope this helps