Which word means not well known?

Which word means "to work hard towards a goal"?

I was ______________________ because I didn't think it was fair that my parents bought my sister ice cream and not me.

She is _______________________ towards her goal of receiving all A's this semester.

Not many people know about this restaurant, making it an __________________ place to get dinner in the city.

Students who continue to talk after the teacher asks them to be quiet are showing obstinacy.

New York City is an obscure place.

Teachers strive to make sure that their students are learning and growing every single day.

Which word means "showing anger over unfair treatment"?