Remember: when there are 2 or more subjects, you use the -an/-en conjugation.
1. trabajan
2. estudian
The answer is c. somos.
Since the subject is nosotros, we have to conjugate the verb to make them match. son matches with 'ellas, ellos, or uds.', somos matches with 'nosotros', eres matches with 'tú', and es matches with 'ello, ella, or ud.'
Most likely D since the noun árbol is masculine and you would use ese in that case.
You understand functions and forms
