I'm kind of confused could I see which one is correct and the steps?

13. A group of eight grade 11 and five grade 12 students wish to be on the senior prom committee. The committee will consist of three students. What is the probability that only grade 12 students will be elected, assuming that all students have an equal chance of being elected? A ) 12 B) 8 C) 5 D) 5 E) 12 F) 8 3 3 3 13 13 13 23 13 13 3 W w