Choose the correct form of the adjective to describe the following noun las estudiantes triste or tristes

to answer this question we need the list of the stores

in my life i wake up get ready for school then i eat breakfast similar to maarit but i do not need to feed chickens or do anything else in the morning. once i am at school i study many different subjects and like maarit my favorite subject is math. then i go home like maarit i do my homework. then unlike maarit i do all my chores right after i do my homework. then i eat dinner and watch t.v until i go to bed. then i wake up and repeat the process once again until the weekend. on the weekend i do nothing i don’t go anywhere with my father i just relax

uhm what exactly is the question?