and Aburrida(option A) means boring and the other options dont make sence for example aburriodos (option b) means bored if youre talking your friends or somthing you wouldnt say the class was bored you would say its boring
Hope this helps
ps. if in another question it says la before the next word that means the answer is mostlikly gonna have la and las cause they are used with femenine words. Masculine words typically end in o or for plural, os.
