Should I challenge this grade?

I took Honors English this semester. The teacher seemed nice and so did the class. Then my papers came in back and forth, rewrite after rewrite, and I keep asking her how my grades were. She said they were fine and she only cared about me learning something. Towards the end of the year, I was caught by surprise. She was showing favoritism to girls who weren't even putting effort in the group work; they weren't talking about the assignments but only how they were going to spend their weekends. My peers never wanted to talk to me. I always got the blame for not participating, even though I participated tremendously outside of groups by raising my hand. I also had perfect attendance. One day I meet with her and she flat out says my papers weren't A material and far from it. So I'm ticked she wasn't warning me about my papers. So I end up getting a B because of her mistake. If I must deal with a B I will. I'm mostly an A student, majoring in English, so this kinda bothers me. Should I challenge it or no? If so, what do I say to argue my grade?